JavaLearn/modernFeatures.html at master · jhavishesh7/JavaLearn · GitHub

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<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Modern JS Features - JavaScript Mastery</title>
  <style>
    body { background: #121212; color: #fff; font-family: sans-serif; padding: 20px; }
    pre { background: #1e1e1e; padding: 10px; border-radius: 5px; margin-bottom: 20px; }
    .output { background: #222; color: #b9f6ca; padding: 12px; border-radius: 5px; min-height: 40px; margin-bottom: 20px; white-space: pre-line; }
    .btn { display: inline-block; background: #4caf50; color: white; font-size: 1.1em; padding: 10px 24px; border-radius: 6px; text-decoration: none; margin-top: 20px; }
    .btn:hover { background: #388e3c; }
    .explanation { background: #263238; color: #ffe082; border-radius: 6px; padding: 18px; margin-top: 30px; font-size: 1.08em; line-height: 1.7; }
    .explanation h2 { color: #ffd600; margin-top: 0; }
  </style>
</head>
<body>
  <h1>Modern JS Features</h1>
  <pre><code>let [x, y] = [1, 2];
let {name, age} = {name: "Alice", age: 25};

let arr1 = [1, 2];
let arr2 = [...arr1, 3, 4];

let text = `Hello ${name}, you are ${age} years old`;

let user = { profile: { name: "Bob" } };
let city = user?.profile?.address?.city;

let setting = null;
let defaultValue = setting ?? "default";

let output = `Destructuring: x=${x}, y=${y}, name=${name}
Spread: ${arr2}
Template: ${text}
Optional Chaining: ${city}
Nullish Coalescing: ${defaultValue}`;

document.getElementById('output').textContent = output;</code></pre>
  <div class="output" id="output"></div>
  <a href="index.html" class="btn">Back to Index</a>
  <div class="explanation">
    <h2>Explanation</h2>
    <ul>
      <li><b>Destructuring</b> — Extracts values from arrays/objects into variables.</li>
      <li><b>Spread operator</b> — Expands arrays into individual elements.</li>
      <li><b>Template literals</b> — Allows embedded expressions in strings using backticks.</li>
      <li><b>Optional chaining</b> — Safely accesses nested properties without errors if something is undefined.</li>
      <li><b>Nullish coalescing</b> — Returns the right value if the left is null or undefined.</li>
      <li>The <b>output</b> variable collects the results and is displayed in the green output box above.</li>
    </ul>
  </div>
  <script>
    let [x, y] = [1, 2];
    let {name, age} = {name: "Alice", age: 25};
    let arr1 = [1, 2];
    let arr2 = [...arr1, 3, 4];
    let text = `Hello ${name}, you are ${age} years old`;
    let user = { profile: { name: "Bob" } };
    let city = user?.profile?.address?.city;
    let setting = null;
    let defaultValue = setting ?? "default";
    let output = `Destructuring: x=${x}, y=${y}, name=${name}
Spread: ${arr2}
Template: ${text}
Optional Chaining: ${city}
Nullish Coalescing: ${defaultValue}`;
    document.getElementById('output').textContent = output;
  </script>
</body>
</html>