Developer Cheat Sheets — CodesCompiler

What are Cheat Sheets?

Cheat sheets are concise quick-reference guides containing the most commonly used syntax, commands, or concepts for a language or tool. Every developer keeps these bookmarked — even experienced ones!

HTML Cheat Sheet

<!-- Document Structure -->
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Page Title</title>
</head>
<body>
  <h1>Heading 1</h1>
  <p>Paragraph text</p>
  <a href="https://example.com">Link</a>
  <img src="image.jpg" alt="Description">
  <ul><li>List item</li></ul>
</body>
</html>

CSS Cheat Sheet

/* Selectors */
element { }        /* Tag selector */
.class { }         /* Class selector */
#id { }            /* ID selector */
a:hover { }        /* Pseudo-class */

/* Box Model */
margin: 10px;      /* Outside element */
padding: 10px;     /* Inside element */
border: 1px solid; /* Border */
width: 100%;       /* Width */

/* Flexbox */
display: flex;
justify-content: center;
align-items: center;
gap: 1rem;

/* CSS Variables */
:root { --primary: #04AA6D; }
color: var(--primary);

JavaScript Cheat Sheet

// Variables
const name = "Alice";    // constant
let age = 25;            // mutable

// Functions
const greet = (name) => `Hello, ${name}!`;

// Array Methods
arr.map(x => x * 2);    // Transform
arr.filter(x => x > 0); // Filter
arr.reduce((a,b) => a+b, 0); // Reduce

// Async/Await
const data = await fetch('/api/data').then(r => r.json());

// Destructuring
const { name, age } = person;
const [first, ...rest] = array;

Git Quick Reference

git init                    # New repo
git clone <url>             # Clone
git add . && git commit -m "msg" # Stage and commit
git push origin main        # Push
git pull                    # Pull latest
git checkout -b branch-name # New branch
git merge branch-name       # Merge
git log --oneline           # Compact log

What's Next?

Practice what you've learned in our full tutorials: HTML, CSS, JavaScript. Or test your knowledge with Quizzes.