Java Programming \u2013 University Level \u2013 Pak Notes Hub<\/title>\r\n <link href=\"https:\/\/fonts.googleapis.com\/css2?family=Inter:wght@400;500;600;700&family=Fira+Code:wght@400;500&display=swap\" rel=\"stylesheet\"\/>\r\n <style>\r\n *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }\r\n :root {\r\n --green:#1a7a4a; --green-dark:#145f38; --green-light:#e8f5ee;\r\n --teal:#17a589; --accent:#f0b127; --dark:#1c2833; --mid:#566573;\r\n --light:#f4f6f7; --code-bg:#f0f4f8; --code-border:#2e86c1;\r\n --note-bg:#fef9e7; --note-border:#f0b127; --white:#ffffff;\r\n --radius:10px; --shadow:0 4px 24px rgba(26,122,74,.10);\r\n }\r\n html { scroll-behavior:smooth; }\r\n body { font-family:'Inter',sans-serif; background:#f2f6f3; color:var(--dark); line-height:1.7; font-size:15px; }\r\n\r\n \/* NAV *\/\r\n nav { position:sticky; top:0; z-index:100; background:var(--green-dark); padding:0 2rem; display:flex; align-items:center; justify-content:space-between; height:56px; 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box-shadow:var(--shadow); }\r\n .congrats h2 { font-size:1.8rem; margin-bottom:.5rem; }\r\n .congrats p { color:#d5f5e3; font-size:1rem; }\r\n\r\n \/* PROGRESS + BACK TOP *\/\r\n .progress-bar { position:fixed; top:0; left:0; height:3px; background:var(--accent); z-index:200; transition:width .1s linear; width:0%; }\r\n #back-top { position:fixed; bottom:2rem; right:2rem; background:var(--green); color:#fff; width:42px; height:42px; border-radius:50%; border:none; cursor:pointer; font-size:1.1rem; box-shadow:0 4px 14px rgba(26,122,74,.35); display:flex; align-items:center; justify-content:center; opacity:0; transition:opacity .25s,transform .25s; pointer-events:none; }\r\n #back-top.visible { opacity:1; pointer-events:auto; }\r\n #back-top:hover { transform:translateY(-2px); }\r\n\r\n @media(max-width:720px){ .page-wrap{grid-template-columns:1fr;} .sidebar{position:static;display:none;} .hero::before{display:none;} nav .nav-links{display:none;} }\r\n <\/style>\r\n<\/head>\r\n<body>\r\n\r\n<div class=\"progress-bar\" id=\"progress\"><\/div>\r\n\r\n<nav>\r\n <div class=\"nav-brand\">Pak <span>Notes Hub<\/span><\/div>\r\n <div class=\"nav-links\">\r\n <a href=\"#toc-section\">Course Outline<\/a>\r\n <a href=\"#unit-1\">Start Learning<\/a>\r\n <a href=\"#unit-7\">OOP in Java<\/a>\r\n <a href=\"#unit-12\">Collections<\/a>\r\n <\/div>\r\n<\/nav>\r\n\r\n<section class=\"hero\">\r\n <div class=\"hero-tag\">\u2615 University Level \u2014 BS CS \/ BS IT<\/div>\r\n <h1>Java Programming<br\/><span>Complete Notes<\/span><\/h1>\r\n <p>Basics to Advanced \u00b7 OOP \u00b7 Collections \u00b7 Multithreading \u2014 All in Easy English<\/p>\r\n <div class=\"hero-pills\">\r\n <span class=\"pill\">\u2615 15 Units<\/span>\r\n <span class=\"pill\">\ud83c\udf93 University Level<\/span>\r\n <span class=\"pill\">\ud83d\udcbb Code Examples<\/span>\r\n <span class=\"pill\">\ud83d\udcdd Practice Tasks<\/span>\r\n <span class=\"pill\">\ud83d\ude80 Final Project<\/span>\r\n <\/div>\r\n<\/section>\r\n\r\n<div class=\"page-wrap\">\r\n\r\n <aside class=\"sidebar\">\r\n <div class=\"sidebar-title\">\ud83d\udccb Course Contents<\/div>\r\n <ul class=\"toc-list\" id=\"toc-nav\">\r\n <li><a href=\"#toc-section\"><span class=\"toc-num\">\ud83d\udccb<\/span> Contents<\/a><\/li>\r\n <li><a href=\"#unit-1\"><span class=\"toc-num\">1<\/span> Intro to Java<\/a><\/li>\r\n <li><a href=\"#unit-2\"><span class=\"toc-num\">2<\/span> Variables & Data Types<\/a><\/li>\r\n <li><a href=\"#unit-3\"><span class=\"toc-num\">3<\/span> Operators<\/a><\/li>\r\n <li><a href=\"#unit-4\"><span class=\"toc-num\">4<\/span> Control Statements<\/a><\/li>\r\n <li><a href=\"#unit-5\"><span class=\"toc-num\">5<\/span> Arrays & Strings<\/a><\/li>\r\n <li><a href=\"#unit-6\"><span class=\"toc-num\">6<\/span> Methods<\/a><\/li>\r\n <li><a href=\"#unit-7\"><span class=\"toc-num\">7<\/span> OOP Basics<\/a><\/li>\r\n <li><a href=\"#unit-8\"><span class=\"toc-num\">8<\/span> Inheritance<\/a><\/li>\r\n <li><a href=\"#unit-9\"><span class=\"toc-num\">9<\/span> Polymorphism<\/a><\/li>\r\n <li><a href=\"#unit-10\"><span class=\"toc-num\">10<\/span> Abstract & Interfaces<\/a><\/li>\r\n <li><a href=\"#unit-11\"><span class=\"toc-num\">11<\/span> Exception Handling<\/a><\/li>\r\n <li><a href=\"#unit-12\"><span class=\"toc-num\">12<\/span> Collections Framework<\/a><\/li>\r\n <li><a href=\"#unit-13\"><span class=\"toc-num\">13<\/span> File I\/O<\/a><\/li>\r\n <li><a href=\"#unit-14\"><span class=\"toc-num\">14<\/span> Multithreading<\/a><\/li>\r\n <li><a href=\"#unit-15\"><span class=\"toc-num\">15<\/span> Final Project<\/a><\/li>\r\n <\/ul>\r\n <\/aside>\r\n\r\n <main>\r\n\r\n <div id=\"toc-section\">\r\n <div class=\"toc-card-header\"><h2>\ud83d\udccb Table of Contents \u2014 15 Units<\/h2><\/div>\r\n <div class=\"toc-card-body\">\r\n <div class=\"toc-grid\">\r\n <a class=\"toc-item\" href=\"#unit-1\"><span class=\"toc-badge\">1<\/span> Introduction to Java<\/a>\r\n <a class=\"toc-item\" href=\"#unit-2\"><span class=\"toc-badge\">2<\/span> Variables & Data Types<\/a>\r\n <a class=\"toc-item\" href=\"#unit-3\"><span class=\"toc-badge\">3<\/span> Operators<\/a>\r\n <a class=\"toc-item\" href=\"#unit-4\"><span class=\"toc-badge\">4<\/span> Control Statements<\/a>\r\n <a class=\"toc-item\" href=\"#unit-5\"><span class=\"toc-badge\">5<\/span> Arrays & Strings<\/a>\r\n <a class=\"toc-item\" href=\"#unit-6\"><span class=\"toc-badge\">6<\/span> Methods<\/a>\r\n <a class=\"toc-item\" href=\"#unit-7\"><span class=\"toc-badge\">7<\/span> OOP Basics<\/a>\r\n <a class=\"toc-item\" href=\"#unit-8\"><span class=\"toc-badge\">8<\/span> Inheritance<\/a>\r\n <a class=\"toc-item\" href=\"#unit-9\"><span class=\"toc-badge\">9<\/span> Polymorphism<\/a>\r\n <a class=\"toc-item\" href=\"#unit-10\"><span class=\"toc-badge\">10<\/span> Abstract Classes & Interfaces<\/a>\r\n <a class=\"toc-item\" href=\"#unit-11\"><span class=\"toc-badge\">11<\/span> Exception Handling<\/a>\r\n <a class=\"toc-item\" href=\"#unit-12\"><span class=\"toc-badge\">12<\/span> Collections Framework<\/a>\r\n <a class=\"toc-item\" href=\"#unit-13\"><span class=\"toc-badge\">13<\/span> File I\/O<\/a>\r\n <a class=\"toc-item\" href=\"#unit-14\"><span class=\"toc-badge\">14<\/span> Multithreading<\/a>\r\n <a class=\"toc-item\" href=\"#unit-15\"><span class=\"toc-badge\">15<\/span> Final Project<\/a>\r\n <\/div>\r\n <\/div>\r\n <\/div>\r\n\r\n \r\n <div class=\"unit\" id=\"unit-1\">\r\n <div class=\"unit-header\">\r\n <span class=\"unit-num-badge\">Unit 1<\/span>\r\n <h2>Introduction to Java<\/h2>\r\n <p>What is Java and why is it everywhere?<\/p>\r\n <\/div>\r\n <div class=\"unit-body\">\r\n <h3>What is Java?<\/h3>\r\n <p><strong>Java<\/strong> is a high-level, object-oriented programming language developed by <strong>James Gosling<\/strong> at Sun Microsystems (now Oracle) in 1995. It's designed to be platform-independent and follows the principle of <strong>\"Write Once, Run Anywhere\" (WORA)<\/strong>.<\/p>\r\n <div class=\"info-box\">\ud83d\udca1 Java is named after Java coffee! The developers loved coffee and chose the name while brainstorming at a local coffee shop.<\/div>\r\n\r\n <h3>Key Features of Java<\/h3>\r\n <div class=\"feature-grid\">\r\n <div class=\"feature-item\">\u2705 Platform Independent<\/div>\r\n <div class=\"feature-item\">\ud83c\udfaf Object-Oriented<\/div>\r\n <div class=\"feature-item\">\ud83d\udd12 Secure<\/div>\r\n <div class=\"feature-item\">\u26a1 Robust & Reliable<\/div>\r\n <div class=\"feature-item\">\ud83e\uddf5 Multithreaded<\/div>\r\n <div class=\"feature-item\">\ud83c\udf10 Distributed<\/div>\r\n <\/div>\r\n\r\n <h3>How Java Works \u2014 JVM, JRE, JDK<\/h3>\r\n <table class=\"data-table\">\r\n <thead><tr><th>Component<\/th><th>Full Name<\/th><th>Purpose<\/th><\/tr><\/thead>\r\n <tbody>\r\n <tr><td>JVM<\/td><td>Java Virtual Machine<\/td><td>Executes Java bytecode, provides platform independence<\/td><\/tr>\r\n <tr><td>JRE<\/td><td>Java Runtime Environment<\/td><td>JVM + libraries needed to run Java programs<\/td><\/tr>\r\n <tr><td>JDK<\/td><td>Java Development Kit<\/td><td>JRE + development tools (compiler, debugger)<\/td><\/tr>\r\n <\/tbody>\r\n <\/table>\r\n\r\n <h3>Java Program Execution Flow<\/h3>\r\n <div class=\"code-block\"><pre>Source Code (.java)\r\n \u2193\r\njavac compiler\r\n \u2193\r\nBytecode (.class)\r\n \u2193\r\nJVM\r\n \u2193\r\nMachine Code (platform-specific)<\/pre><\/div>\r\n\r\n <h3>Your First Java Program<\/h3>\r\n <div class=\"code-block\"><pre><span class=\"kw\">public class<\/span> HelloWorld {\r\n <span class=\"kw\">public static void<\/span> main(String[] args) {\r\n System.out.println(<span class=\"st\">\"Hello, World!\"<\/span>);\r\n }\r\n}\r\n\r\n<span class=\"cm\">\/\/ Output: Hello, World!<\/span><\/pre><\/div>\r\n\r\n <h3>Java vs Other Languages<\/h3>\r\n <table class=\"data-table\">\r\n <thead><tr><th>Feature<\/th><th>Java<\/th><th>C++<\/th><th>Python<\/th><\/tr><\/thead>\r\n <tbody>\r\n <tr><td>Platform<\/td><td>Platform Independent<\/td><td>Platform Dependent<\/td><td>Platform Independent<\/td><\/tr>\r\n <tr><td>Memory<\/td><td>Automatic (Garbage Collection)<\/td><td>Manual<\/td><td>Automatic<\/td><\/tr>\r\n <tr><td>Speed<\/td><td>Fast<\/td><td>Faster<\/td><td>Slower<\/td><\/tr>\r\n <tr><td>Syntax<\/td><td>Moderate<\/td><td>Complex<\/td><td>Simple<\/td><\/tr>\r\n <tr><td>Use Case<\/td><td>Enterprise, Android<\/td><td>System software, games<\/td><td>AI, web, scripting<\/td><\/tr>\r\n <\/tbody>\r\n <\/table>\r\n\r\n <div class=\"practice\"><strong>\u270f\ufe0f Practice:<\/strong> Install JDK on your computer. Write and compile a program that prints your name and university. Run it using java command.<\/div>\r\n <\/div>\r\n <\/div>\r\n\r\n \r\n <div class=\"unit\" id=\"unit-2\">\r\n <div class=\"unit-header\">\r\n <span class=\"unit-num-badge\">Unit 2<\/span>\r\n <h2>Variables & Data Types<\/h2>\r\n <p>Storing and managing data in Java.<\/p>\r\n <\/div>\r\n <div class=\"unit-body\">\r\n <h3>Variables in Java<\/h3>\r\n <p>A <strong>variable<\/strong> is a named container that stores data. In Java, you must declare the variable type before using it.<\/p>\r\n <div class=\"code-block\"><pre><span class=\"kw\">int<\/span> age = 20;\r\n<span class=\"kw\">double<\/span> price = 99.99;\r\n<span class=\"kw\">String<\/span> name = <span class=\"st\">\"Ali\"<\/span>;\r\n<span class=\"kw\">boolean<\/span> isStudent = <span class=\"kw\">true<\/span>;<\/pre><\/div>\r\n\r\n <h3>Data Types in Java<\/h3>\r\n <table class=\"data-table\">\r\n <thead><tr><th>Type<\/th><th>Size<\/th><th>Range\/Values<\/th><th>Example<\/th><\/tr><\/thead>\r\n <tbody>\r\n <tr><td>byte<\/td><td>1 byte<\/td><td>-128 to 127<\/td><td>byte b = 100;<\/td><\/tr>\r\n <tr><td>short<\/td><td>2 bytes<\/td><td>-32,768 to 32,767<\/td><td>short s = 5000;<\/td><\/tr>\r\n <tr><td>int<\/td><td>4 bytes<\/td><td>-2\u00b3\u00b9 to 2\u00b3\u00b9-1<\/td><td>int num = 12345;<\/td><\/tr>\r\n <tr><td>long<\/td><td>8 bytes<\/td><td>-2\u2076\u00b3 to 2\u2076\u00b3-1<\/td><td>long l = 100000L;<\/td><\/tr>\r\n <tr><td>float<\/td><td>4 bytes<\/td><td>~7 decimal digits<\/td><td>float f = 3.14f;<\/td><\/tr>\r\n <tr><td>double<\/td><td>8 bytes<\/td><td>~15 decimal digits<\/td><td>double d = 3.14159;<\/td><\/tr>\r\n <tr><td>char<\/td><td>2 bytes<\/td><td>Unicode character<\/td><td>char c = 'A';<\/td><\/tr>\r\n <tr><td>boolean<\/td><td>1 bit<\/td><td>true or false<\/td><td>boolean b = true;<\/td><\/tr>\r\n <\/tbody>\r\n <\/table>\r\n\r\n <h3>Type Casting<\/h3>\r\n <p><strong>Widening (Automatic):<\/strong> byte \u2192 short \u2192 int \u2192 long \u2192 float \u2192 double<\/p>\r\n <div class=\"code-block\"><pre><span class=\"kw\">int<\/span> i = 100;\r\n<span class=\"kw\">double<\/span> d = i; <span class=\"cm\">\/\/ Automatic casting<\/span><\/pre><\/div>\r\n\r\n <p><strong>Narrowing (Manual):<\/strong> double \u2192 float \u2192 long \u2192 int \u2192 short \u2192 byte<\/p>\r\n <div class=\"code-block\"><pre><span class=\"kw\">double<\/span> d = 99.99;\r\n<span class=\"kw\">int<\/span> i = (<span class=\"kw\">int<\/span>) d; <span class=\"cm\">\/\/ i = 99 (decimal part lost)<\/span><\/pre><\/div>\r\n\r\n <h3>Constants (final keyword)<\/h3>\r\n <div class=\"code-block\"><pre><span class=\"kw\">final int<\/span> MAX_AGE = 100;\r\n<span class=\"cm\">\/\/ MAX_AGE = 200; \/\/ Error! Cannot modify<\/span><\/pre><\/div>\r\n\r\n <div class=\"practice\"><strong>\u270f\ufe0f Practice:<\/strong> Declare variables for: student name (String), roll number (int), CGPA (double), and pass status (boolean). Print all values.<\/div>\r\n <\/div>\r\n <\/div>\r\n\r\n \r\n <div class=\"unit\" id=\"unit-3\">\r\n <div class=\"unit-header\">\r\n <span class=\"unit-num-badge\">Unit 3<\/span>\r\n <h2>Operators in Java<\/h2>\r\n <p>Performing operations on data \u2014 arithmetic, logical, and more.<\/p>\r\n <\/div>\r\n <div class=\"unit-body\">\r\n <h3>Types of Operators<\/h3>\r\n <table class=\"data-table\">\r\n <thead><tr><th>Type<\/th><th>Operators<\/th><th>Example<\/th><\/tr><\/thead>\r\n <tbody>\r\n <tr><td>Arithmetic<\/td><td>+, -, *, \/, %<\/td><td>5 + 3 = 8<\/td><\/tr>\r\n <tr><td>Relational<\/td><td>==, !=, >, <, >=, <=<\/td><td>5 > 3 \u2192 true<\/td><\/tr>\r\n <tr><td>Logical<\/td><td>&& (AND), || (OR), ! (NOT)<\/td><td>true && false \u2192 false<\/td><\/tr>\r\n <tr><td>Assignment<\/td><td>=, +=, -=, *=, \/=<\/td><td>x += 5<\/td><\/tr>\r\n <tr><td>Unary<\/td><td>++, --, +, -, !<\/td><td>x++<\/td><\/tr>\r\n <tr><td>Ternary<\/td><td>? :<\/td><td>x > 5 ? \"yes\" : \"no\"<\/td><\/tr>\r\n <\/tbody>\r\n <\/table>\r\n\r\n <h3>Increment & Decrement<\/h3>\r\n <div class=\"code-block\"><pre><span class=\"kw\">int<\/span> x = 5;\r\nx++; <span class=\"cm\">\/\/ Post-increment: use then increment \u2192 x = 6<\/span>\r\n++x; <span class=\"cm\">\/\/ Pre-increment: increment then use \u2192 x = 7<\/span>\r\n\r\n<span class=\"kw\">int<\/span> a = 10;\r\n<span class=\"kw\">int<\/span> b = a++; <span class=\"cm\">\/\/ b = 10, then a = 11<\/span>\r\n<span class=\"kw\">int<\/span> c = ++a; <span class=\"cm\">\/\/ a = 12, then c = 12<\/span><\/pre><\/div>\r\n\r\n <div class=\"practice\"><strong>\u270f\ufe0f Practice:<\/strong> Write a program to swap two numbers without using a third variable using arithmetic operators.<\/div>\r\n <\/div>\r\n <\/div>\r\n\r\n <div class=\"congrats\">\r\n <h2>\ud83c\udf89 Congratulations!<\/h2>\r\n <p>You've completed the Java Programming course! Keep practicing and building projects. Best of luck! \u2615\ud83c\udf1f<\/p>\r\n <\/div>\r\n\r\n <\/main>\r\n<\/div>\r\n\r\n<button id=\"back-top\" aria-label=\"Back to top\">\u2191<\/button>\r\n\r\n<script>\r\nwindow.addEventListener('scroll', () => {\r\n const winScroll = document.body.scrollTop || document.documentElement.scrollTop;\r\n const height = document.documentElement.scrollHeight - document.documentElement.clientHeight;\r\n const scrolled = (winScroll \/ height) * 100;\r\n document.getElementById('progress').style.width = scrolled + '%';\r\n});\r\n\r\nconst backTop = document.getElementById('back-top');\r\nwindow.addEventListener('scroll', () => {\r\n if (window.pageYOffset > 300) {\r\n backTop.classList.add('visible');\r\n } else {\r\n backTop.classList.remove('visible');\r\n }\r\n});\r\nbackTop.addEventListener('click', () => {\r\n window.scrollTo({ top: 0, behavior: 'smooth' });\r\n});\r\n\r\nconst sections = document.querySelectorAll('.unit');\r\nconst navLinks = document.querySelectorAll('.toc-list a');\r\n\r\nwindow.addEventListener('scroll', () => {\r\n let current = '';\r\n sections.forEach(section => {\r\n const sectionTop = section.offsetTop;\r\n if (pageYOffset >= sectionTop - 100) {\r\n current = section.getAttribute('id');\r\n }\r\n });\r\n\r\n navLinks.forEach(link => {\r\n link.classList.remove('active');\r\n if (link.getAttribute('href') === '#' + current) {\r\n link.classList.add('active');\r\n }\r\n });\r\n});\r\n<\/script>\r\n\r\n<\/body>\r\n<\/html>\r\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Java Programming \u2013 University Level \u2013 Pak Notes Hub Pak Notes Hub Course Outline Start Learning OOP in Java Collections \u2615 University Level \u2014 BS CS \/ BS IT Java ProgrammingComplete Notes Basics to Advanced \u00b7 OOP \u00b7 Collections \u00b7 Multithreading \u2014 All in Easy English \u2615 15 Units \ud83c\udf93 University Level \ud83d\udcbb Code Examples […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_angie_page":false,"footnotes":""},"class_list":["post-468","page","type-page","status-publish","hentry"],"_hostinger_reach_plugin_has_subscription_block":false,"_hostinger_reach_plugin_is_elementor":false,"_links":{"self":[{"href":"https:\/\/paknoteshub.online\/index.php?rest_route=\/wp\/v2\/pages\/468","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/paknoteshub.online\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/paknoteshub.online\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/paknoteshub.online\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/paknoteshub.online\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=468"}],"version-history":[{"count":4,"href":"https:\/\/paknoteshub.online\/index.php?rest_route=\/wp\/v2\/pages\/468\/revisions"}],"predecessor-version":[{"id":473,"href":"https:\/\/paknoteshub.online\/index.php?rest_route=\/wp\/v2\/pages\/468\/revisions\/473"}],"wp:attachment":[{"href":"https:\/\/paknoteshub.online\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=468"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

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\n\t\t\t\t\t\r\n\r\n\r\n \r\n \r\n Java Programming \u2013 University Level \u2013 Pak Notes Hub<\/title>\r\n <link href=\"https:\/\/fonts.googleapis.com\/css2?family=Inter:wght@400;500;600;700&family=Fira+Code:wght@400;500&display=swap\" rel=\"stylesheet\"\/>\r\n <style>\r\n *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }\r\n :root {\r\n --green:#1a7a4a; --green-dark:#145f38; --green-light:#e8f5ee;\r\n --teal:#17a589; --accent:#f0b127; --dark:#1c2833; --mid:#566573;\r\n --light:#f4f6f7; --code-bg:#f0f4f8; --code-border:#2e86c1;\r\n --note-bg:#fef9e7; --note-border:#f0b127; --white:#ffffff;\r\n --radius:10px; --shadow:0 4px 24px rgba(26,122,74,.10);\r\n }\r\n html { scroll-behavior:smooth; }\r\n body { font-family:'Inter',sans-serif; background:#f2f6f3; color:var(--dark); line-height:1.7; font-size:15px; }\r\n\r\n \/* NAV *\/\r\n nav { position:sticky; top:0; z-index:100; background:var(--green-dark); padding:0 2rem; display:flex; align-items:center; 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grid-template-columns:repeat(auto-fill,minmax(210px,1fr)); gap:.6rem; margin:.9rem 0 1.2rem; }\r\n .feature-item { background:var(--green-light); border-radius:7px; padding:.6rem .9rem; font-size:.85rem; display:flex; align-items:center; gap:.5rem; color:var(--green-dark); border:1px solid #a2d9b5; font-weight:500; }\r\n\r\n \/* CONCEPT GRID *\/\r\n .concept-grid { display:grid; grid-template-columns:repeat(auto-fill,minmax(190px,1fr)); gap:.8rem; margin:.9rem 0 1.2rem; }\r\n .concept-card { background:var(--green-light); border:1px solid #a2d9b5; border-radius:8px; padding:.85rem 1rem; }\r\n .concept-card .concept-name { font-weight:700; color:var(--green); font-size:.92rem; margin-bottom:.3rem; }\r\n .concept-card .concept-rule { font-size:.8rem; color:var(--mid); }\r\n\r\n \/* TOC CARD *\/\r\n #toc-section { background:var(--white); border-radius:var(--radius); box-shadow:var(--shadow); margin-bottom:2.5rem; overflow:hidden; }\r\n .toc-card-header { 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0%,#145f38 100%); border-radius:var(--radius); padding:2.5rem 2rem; text-align:center; color:#fff; margin-bottom:2.5rem; box-shadow:var(--shadow); }\r\n .congrats h2 { font-size:1.8rem; margin-bottom:.5rem; }\r\n .congrats p { color:#d5f5e3; font-size:1rem; }\r\n\r\n \/* PROGRESS + BACK TOP *\/\r\n .progress-bar { position:fixed; top:0; left:0; height:3px; background:var(--accent); z-index:200; transition:width .1s linear; width:0%; }\r\n #back-top { position:fixed; bottom:2rem; right:2rem; background:var(--green); color:#fff; width:42px; height:42px; border-radius:50%; border:none; cursor:pointer; font-size:1.1rem; box-shadow:0 4px 14px rgba(26,122,74,.35); display:flex; align-items:center; justify-content:center; opacity:0; transition:opacity .25s,transform .25s; pointer-events:none; }\r\n #back-top.visible { opacity:1; pointer-events:auto; }\r\n #back-top:hover { transform:translateY(-2px); }\r\n\r\n @media(max-width:720px){ .page-wrap{grid-template-columns:1fr;} .sidebar{position:static;display:none;} .hero::before{display:none;} nav .nav-links{display:none;} }\r\n <\/style>\r\n<\/head>\r\n<body>\r\n\r\n<div class=\"progress-bar\" id=\"progress\"><\/div>\r\n\r\n<nav>\r\n <div class=\"nav-brand\">Pak <span>Notes Hub<\/span><\/div>\r\n <div class=\"nav-links\">\r\n <a href=\"#toc-section\">Course Outline<\/a>\r\n <a href=\"#unit-1\">Start Learning<\/a>\r\n <a href=\"#unit-7\">OOP in Java<\/a>\r\n <a href=\"#unit-12\">Collections<\/a>\r\n <\/div>\r\n<\/nav>\r\n\r\n<section class=\"hero\">\r\n <div class=\"hero-tag\">\u2615 University Level \u2014 BS CS \/ BS IT<\/div>\r\n <h1>Java Programming<br\/><span>Complete Notes<\/span><\/h1>\r\n <p>Basics to Advanced \u00b7 OOP \u00b7 Collections \u00b7 Multithreading \u2014 All in Easy English<\/p>\r\n <div class=\"hero-pills\">\r\n <span class=\"pill\">\u2615 15 Units<\/span>\r\n <span class=\"pill\">\ud83c\udf93 University Level<\/span>\r\n <span class=\"pill\">\ud83d\udcbb Code Examples<\/span>\r\n <span class=\"pill\">\ud83d\udcdd Practice Tasks<\/span>\r\n <span class=\"pill\">\ud83d\ude80 Final Project<\/span>\r\n <\/div>\r\n<\/section>\r\n\r\n<div class=\"page-wrap\">\r\n\r\n <aside class=\"sidebar\">\r\n <div class=\"sidebar-title\">\ud83d\udccb Course Contents<\/div>\r\n <ul class=\"toc-list\" id=\"toc-nav\">\r\n <li><a href=\"#toc-section\"><span class=\"toc-num\">\ud83d\udccb<\/span> Contents<\/a><\/li>\r\n <li><a href=\"#unit-1\"><span class=\"toc-num\">1<\/span> Intro to Java<\/a><\/li>\r\n <li><a href=\"#unit-2\"><span class=\"toc-num\">2<\/span> Variables & Data Types<\/a><\/li>\r\n <li><a href=\"#unit-3\"><span class=\"toc-num\">3<\/span> Operators<\/a><\/li>\r\n <li><a href=\"#unit-4\"><span class=\"toc-num\">4<\/span> Control Statements<\/a><\/li>\r\n <li><a href=\"#unit-5\"><span class=\"toc-num\">5<\/span> Arrays & Strings<\/a><\/li>\r\n <li><a href=\"#unit-6\"><span class=\"toc-num\">6<\/span> Methods<\/a><\/li>\r\n <li><a href=\"#unit-7\"><span class=\"toc-num\">7<\/span> OOP Basics<\/a><\/li>\r\n <li><a href=\"#unit-8\"><span class=\"toc-num\">8<\/span> Inheritance<\/a><\/li>\r\n <li><a href=\"#unit-9\"><span class=\"toc-num\">9<\/span> Polymorphism<\/a><\/li>\r\n <li><a href=\"#unit-10\"><span class=\"toc-num\">10<\/span> Abstract & Interfaces<\/a><\/li>\r\n <li><a href=\"#unit-11\"><span class=\"toc-num\">11<\/span> Exception Handling<\/a><\/li>\r\n <li><a href=\"#unit-12\"><span class=\"toc-num\">12<\/span> Collections Framework<\/a><\/li>\r\n <li><a href=\"#unit-13\"><span class=\"toc-num\">13<\/span> File I\/O<\/a><\/li>\r\n <li><a href=\"#unit-14\"><span class=\"toc-num\">14<\/span> Multithreading<\/a><\/li>\r\n <li><a href=\"#unit-15\"><span class=\"toc-num\">15<\/span> Final Project<\/a><\/li>\r\n <\/ul>\r\n <\/aside>\r\n\r\n <main>\r\n\r\n <div id=\"toc-section\">\r\n <div class=\"toc-card-header\"><h2>\ud83d\udccb Table of Contents \u2014 15 Units<\/h2><\/div>\r\n <div class=\"toc-card-body\">\r\n <div class=\"toc-grid\">\r\n <a class=\"toc-item\" href=\"#unit-1\"><span class=\"toc-badge\">1<\/span> Introduction to Java<\/a>\r\n <a class=\"toc-item\" href=\"#unit-2\"><span class=\"toc-badge\">2<\/span> Variables & Data Types<\/a>\r\n <a class=\"toc-item\" href=\"#unit-3\"><span class=\"toc-badge\">3<\/span> Operators<\/a>\r\n <a class=\"toc-item\" href=\"#unit-4\"><span class=\"toc-badge\">4<\/span> Control Statements<\/a>\r\n <a class=\"toc-item\" href=\"#unit-5\"><span class=\"toc-badge\">5<\/span> Arrays & Strings<\/a>\r\n <a class=\"toc-item\" href=\"#unit-6\"><span class=\"toc-badge\">6<\/span> Methods<\/a>\r\n <a class=\"toc-item\" href=\"#unit-7\"><span class=\"toc-badge\">7<\/span> OOP Basics<\/a>\r\n <a class=\"toc-item\" href=\"#unit-8\"><span class=\"toc-badge\">8<\/span> Inheritance<\/a>\r\n <a class=\"toc-item\" href=\"#unit-9\"><span class=\"toc-badge\">9<\/span> Polymorphism<\/a>\r\n <a class=\"toc-item\" href=\"#unit-10\"><span class=\"toc-badge\">10<\/span> Abstract Classes & Interfaces<\/a>\r\n <a class=\"toc-item\" href=\"#unit-11\"><span class=\"toc-badge\">11<\/span> Exception Handling<\/a>\r\n <a class=\"toc-item\" href=\"#unit-12\"><span class=\"toc-badge\">12<\/span> Collections Framework<\/a>\r\n <a class=\"toc-item\" href=\"#unit-13\"><span class=\"toc-badge\">13<\/span> File I\/O<\/a>\r\n <a class=\"toc-item\" href=\"#unit-14\"><span class=\"toc-badge\">14<\/span> Multithreading<\/a>\r\n <a class=\"toc-item\" href=\"#unit-15\"><span class=\"toc-badge\">15<\/span> Final Project<\/a>\r\n <\/div>\r\n <\/div>\r\n <\/div>\r\n\r\n \r\n <div class=\"unit\" id=\"unit-1\">\r\n <div class=\"unit-header\">\r\n <span class=\"unit-num-badge\">Unit 1<\/span>\r\n <h2>Introduction to Java<\/h2>\r\n <p>What is Java and why is it everywhere?<\/p>\r\n <\/div>\r\n <div class=\"unit-body\">\r\n <h3>What is Java?<\/h3>\r\n <p><strong>Java<\/strong> is a high-level, object-oriented programming language developed by <strong>James Gosling<\/strong> at Sun Microsystems (now Oracle) in 1995. It's designed to be platform-independent and follows the principle of <strong>\"Write Once, Run Anywhere\" (WORA)<\/strong>.<\/p>\r\n <div class=\"info-box\">\ud83d\udca1 Java is named after Java coffee! The developers loved coffee and chose the name while brainstorming at a local coffee shop.<\/div>\r\n\r\n <h3>Key Features of Java<\/h3>\r\n <div class=\"feature-grid\">\r\n <div class=\"feature-item\">\u2705 Platform Independent<\/div>\r\n <div class=\"feature-item\">\ud83c\udfaf Object-Oriented<\/div>\r\n <div class=\"feature-item\">\ud83d\udd12 Secure<\/div>\r\n <div class=\"feature-item\">\u26a1 Robust & Reliable<\/div>\r\n <div class=\"feature-item\">\ud83e\uddf5 Multithreaded<\/div>\r\n <div class=\"feature-item\">\ud83c\udf10 Distributed<\/div>\r\n <\/div>\r\n\r\n <h3>How Java Works \u2014 JVM, JRE, JDK<\/h3>\r\n <table class=\"data-table\">\r\n <thead><tr><th>Component<\/th><th>Full Name<\/th><th>Purpose<\/th><\/tr><\/thead>\r\n <tbody>\r\n <tr><td>JVM<\/td><td>Java Virtual Machine<\/td><td>Executes Java bytecode, provides platform independence<\/td><\/tr>\r\n <tr><td>JRE<\/td><td>Java Runtime Environment<\/td><td>JVM + libraries needed to run Java programs<\/td><\/tr>\r\n <tr><td>JDK<\/td><td>Java Development Kit<\/td><td>JRE + development tools (compiler, debugger)<\/td><\/tr>\r\n <\/tbody>\r\n <\/table>\r\n\r\n <h3>Java Program Execution Flow<\/h3>\r\n <div class=\"code-block\"><pre>Source Code (.java)\r\n \u2193\r\njavac compiler\r\n \u2193\r\nBytecode (.class)\r\n \u2193\r\nJVM\r\n \u2193\r\nMachine Code (platform-specific)<\/pre><\/div>\r\n\r\n <h3>Your First Java Program<\/h3>\r\n <div class=\"code-block\"><pre><span class=\"kw\">public class<\/span> HelloWorld {\r\n <span class=\"kw\">public static void<\/span> main(String[] args) {\r\n System.out.println(<span class=\"st\">\"Hello, World!\"<\/span>);\r\n }\r\n}\r\n\r\n<span class=\"cm\">\/\/ Output: Hello, World!<\/span><\/pre><\/div>\r\n\r\n <h3>Java vs Other Languages<\/h3>\r\n <table class=\"data-table\">\r\n <thead><tr><th>Feature<\/th><th>Java<\/th><th>C++<\/th><th>Python<\/th><\/tr><\/thead>\r\n <tbody>\r\n <tr><td>Platform<\/td><td>Platform Independent<\/td><td>Platform Dependent<\/td><td>Platform Independent<\/td><\/tr>\r\n <tr><td>Memory<\/td><td>Automatic (Garbage Collection)<\/td><td>Manual<\/td><td>Automatic<\/td><\/tr>\r\n <tr><td>Speed<\/td><td>Fast<\/td><td>Faster<\/td><td>Slower<\/td><\/tr>\r\n <tr><td>Syntax<\/td><td>Moderate<\/td><td>Complex<\/td><td>Simple<\/td><\/tr>\r\n <tr><td>Use Case<\/td><td>Enterprise, Android<\/td><td>System software, games<\/td><td>AI, web, scripting<\/td><\/tr>\r\n <\/tbody>\r\n <\/table>\r\n\r\n <div class=\"practice\"><strong>\u270f\ufe0f Practice:<\/strong> Install JDK on your computer. Write and compile a program that prints your name and university. Run it using java command.<\/div>\r\n <\/div>\r\n <\/div>\r\n\r\n \r\n <div class=\"unit\" id=\"unit-2\">\r\n <div class=\"unit-header\">\r\n <span class=\"unit-num-badge\">Unit 2<\/span>\r\n <h2>Variables & Data Types<\/h2>\r\n <p>Storing and managing data in Java.<\/p>\r\n <\/div>\r\n <div class=\"unit-body\">\r\n <h3>Variables in Java<\/h3>\r\n <p>A <strong>variable<\/strong> is a named container that stores data. In Java, you must declare the variable type before using it.<\/p>\r\n <div class=\"code-block\"><pre><span class=\"kw\">int<\/span> age = 20;\r\n<span class=\"kw\">double<\/span> price = 99.99;\r\n<span class=\"kw\">String<\/span> name = <span class=\"st\">\"Ali\"<\/span>;\r\n<span class=\"kw\">boolean<\/span> isStudent = <span class=\"kw\">true<\/span>;<\/pre><\/div>\r\n\r\n <h3>Data Types in Java<\/h3>\r\n <table class=\"data-table\">\r\n <thead><tr><th>Type<\/th><th>Size<\/th><th>Range\/Values<\/th><th>Example<\/th><\/tr><\/thead>\r\n <tbody>\r\n <tr><td>byte<\/td><td>1 byte<\/td><td>-128 to 127<\/td><td>byte b = 100;<\/td><\/tr>\r\n <tr><td>short<\/td><td>2 bytes<\/td><td>-32,768 to 32,767<\/td><td>short s = 5000;<\/td><\/tr>\r\n <tr><td>int<\/td><td>4 bytes<\/td><td>-2\u00b3\u00b9 to 2\u00b3\u00b9-1<\/td><td>int num = 12345;<\/td><\/tr>\r\n <tr><td>long<\/td><td>8 bytes<\/td><td>-2\u2076\u00b3 to 2\u2076\u00b3-1<\/td><td>long l = 100000L;<\/td><\/tr>\r\n <tr><td>float<\/td><td>4 bytes<\/td><td>~7 decimal digits<\/td><td>float f = 3.14f;<\/td><\/tr>\r\n <tr><td>double<\/td><td>8 bytes<\/td><td>~15 decimal digits<\/td><td>double d = 3.14159;<\/td><\/tr>\r\n <tr><td>char<\/td><td>2 bytes<\/td><td>Unicode character<\/td><td>char c = 'A';<\/td><\/tr>\r\n <tr><td>boolean<\/td><td>1 bit<\/td><td>true or false<\/td><td>boolean b = true;<\/td><\/tr>\r\n <\/tbody>\r\n <\/table>\r\n\r\n <h3>Type Casting<\/h3>\r\n <p><strong>Widening (Automatic):<\/strong> byte \u2192 short \u2192 int \u2192 long \u2192 float \u2192 double<\/p>\r\n <div class=\"code-block\"><pre><span class=\"kw\">int<\/span> i = 100;\r\n<span class=\"kw\">double<\/span> d = i; <span class=\"cm\">\/\/ Automatic casting<\/span><\/pre><\/div>\r\n\r\n <p><strong>Narrowing (Manual):<\/strong> double \u2192 float \u2192 long \u2192 int \u2192 short \u2192 byte<\/p>\r\n <div class=\"code-block\"><pre><span class=\"kw\">double<\/span> d = 99.99;\r\n<span class=\"kw\">int<\/span> i = (<span class=\"kw\">int<\/span>) d; <span class=\"cm\">\/\/ i = 99 (decimal part lost)<\/span><\/pre><\/div>\r\n\r\n <h3>Constants (final keyword)<\/h3>\r\n <div class=\"code-block\"><pre><span class=\"kw\">final int<\/span> MAX_AGE = 100;\r\n<span class=\"cm\">\/\/ MAX_AGE = 200; \/\/ Error! Cannot modify<\/span><\/pre><\/div>\r\n\r\n <div class=\"practice\"><strong>\u270f\ufe0f Practice:<\/strong> Declare variables for: student name (String), roll number (int), CGPA (double), and pass status (boolean). Print all values.<\/div>\r\n <\/div>\r\n <\/div>\r\n\r\n \r\n <div class=\"unit\" id=\"unit-3\">\r\n <div class=\"unit-header\">\r\n <span class=\"unit-num-badge\">Unit 3<\/span>\r\n <h2>Operators in Java<\/h2>\r\n <p>Performing operations on data \u2014 arithmetic, logical, and more.<\/p>\r\n <\/div>\r\n <div class=\"unit-body\">\r\n <h3>Types of Operators<\/h3>\r\n <table class=\"data-table\">\r\n <thead><tr><th>Type<\/th><th>Operators<\/th><th>Example<\/th><\/tr><\/thead>\r\n <tbody>\r\n <tr><td>Arithmetic<\/td><td>+, -, *, \/, %<\/td><td>5 + 3 = 8<\/td><\/tr>\r\n <tr><td>Relational<\/td><td>==, !=, >, <, >=, <=<\/td><td>5 > 3 \u2192 true<\/td><\/tr>\r\n <tr><td>Logical<\/td><td>&& (AND), || (OR), ! (NOT)<\/td><td>true && false \u2192 false<\/td><\/tr>\r\n <tr><td>Assignment<\/td><td>=, +=, -=, *=, \/=<\/td><td>x += 5<\/td><\/tr>\r\n <tr><td>Unary<\/td><td>++, --, +, -, !<\/td><td>x++<\/td><\/tr>\r\n <tr><td>Ternary<\/td><td>? :<\/td><td>x > 5 ? \"yes\" : \"no\"<\/td><\/tr>\r\n <\/tbody>\r\n <\/table>\r\n\r\n <h3>Increment & Decrement<\/h3>\r\n <div class=\"code-block\"><pre><span class=\"kw\">int<\/span> x = 5;\r\nx++; <span class=\"cm\">\/\/ Post-increment: use then increment \u2192 x = 6<\/span>\r\n++x; <span class=\"cm\">\/\/ Pre-increment: increment then use \u2192 x = 7<\/span>\r\n\r\n<span class=\"kw\">int<\/span> a = 10;\r\n<span class=\"kw\">int<\/span> b = a++; <span class=\"cm\">\/\/ b = 10, then a = 11<\/span>\r\n<span class=\"kw\">int<\/span> c = ++a; <span class=\"cm\">\/\/ a = 12, then c = 12<\/span><\/pre><\/div>\r\n\r\n <div class=\"practice\"><strong>\u270f\ufe0f Practice:<\/strong> Write a program to swap two numbers without using a third variable using arithmetic operators.<\/div>\r\n <\/div>\r\n <\/div>\r\n\r\n <div class=\"congrats\">\r\n <h2>\ud83c\udf89 Congratulations!<\/h2>\r\n <p>You've completed the Java Programming course! Keep practicing and building projects. Best of luck! \u2615\ud83c\udf1f<\/p>\r\n <\/div>\r\n\r\n <\/main>\r\n<\/div>\r\n\r\n<button id=\"back-top\" aria-label=\"Back to top\">\u2191<\/button>\r\n\r\n<script>\r\nwindow.addEventListener('scroll', () => {\r\n const winScroll = document.body.scrollTop || document.documentElement.scrollTop;\r\n const height = document.documentElement.scrollHeight - document.documentElement.clientHeight;\r\n const scrolled = (winScroll \/ height) * 100;\r\n document.getElementById('progress').style.width = scrolled + '%';\r\n});\r\n\r\nconst backTop = document.getElementById('back-top');\r\nwindow.addEventListener('scroll', () => {\r\n if (window.pageYOffset > 300) {\r\n backTop.classList.add('visible');\r\n } else {\r\n backTop.classList.remove('visible');\r\n }\r\n});\r\nbackTop.addEventListener('click', () => {\r\n window.scrollTo({ top: 0, behavior: 'smooth' });\r\n});\r\n\r\nconst sections = document.querySelectorAll('.unit');\r\nconst navLinks = document.querySelectorAll('.toc-list a');\r\n\r\nwindow.addEventListener('scroll', () => {\r\n let current = '';\r\n sections.forEach(section => {\r\n const sectionTop = section.offsetTop;\r\n if (pageYOffset >= sectionTop - 100) {\r\n current = section.getAttribute('id');\r\n }\r\n });\r\n\r\n navLinks.forEach(link => {\r\n link.classList.remove('active');\r\n if (link.getAttribute('href') === '#' + current) {\r\n link.classList.add('active');\r\n }\r\n });\r\n});\r\n<\/script>\r\n\r\n<\/body>\r\n<\/html>\r\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Java Programming \u2013 University Level \u2013 Pak Notes Hub Pak Notes Hub Course Outline Start Learning OOP in Java Collections \u2615 University Level \u2014 BS CS \/ BS IT Java ProgrammingComplete Notes Basics to Advanced \u00b7 OOP \u00b7 Collections \u00b7 Multithreading \u2014 All in Easy English \u2615 15 Units \ud83c\udf93 University Level \ud83d\udcbb Code Examples […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_angie_page":false,"footnotes":""},"class_list":["post-468","page","type-page","status-publish","hentry"],"_hostinger_reach_plugin_has_subscription_block":false,"_hostinger_reach_plugin_is_elementor":false,"_links":{"self":[{"href":"https:\/\/paknoteshub.online\/index.php?rest_route=\/wp\/v2\/pages\/468","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/paknoteshub.online\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/paknoteshub.online\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/paknoteshub.online\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/paknoteshub.online\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=468"}],"version-history":[{"count":4,"href":"https:\/\/paknoteshub.online\/index.php?rest_route=\/wp\/v2\/pages\/468\/revisions"}],"predecessor-version":[{"id":473,"href":"https:\/\/paknoteshub.online\/index.php?rest_route=\/wp\/v2\/pages\/468\/revisions\/473"}],"wp:attachment":[{"href":"https:\/\/paknoteshub.online\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=468"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}