Cheatsheets
Quick reference guides for common syntax, commands, and patterns. Use these to refresh your memory while coding or debugging.
Why Use Cheatsheets?
- Faster recall: Stop context-switching to docs for basics.
- Reduce mistakes: Double-check flags, syntax, and commands.
- Learn patterns: Keep common templates close at hand.
- Great for interviews: Review core topics quickly.
Common Use Cases
🛠️ Debugging
Confirm flags, status codes, and command syntax while troubleshooting.
🧑💻 Daily development
Keep key language and framework patterns close during coding sessions.
📚 Learning & refresh
Revisit essentials without reading long documentation pages.
🧪 Prototyping
Copy/paste common snippets to get started quickly.
How to Use This Page
- Pick a topic: Scroll to the cheatsheet you need (Regex, Python, React, etc.).
- Copy patterns: Use the snippets as a starting point in your project.
- Validate output: For code transforms, use the related tools in the sidebar.
💡 Tip: Combine these with tools like Regex Tester, JSON Validator, and SQL Formatter for faster workflows.
Regex Flags
- g — global
- i — ignore case
- m — multiline
- s — dotAll
- u — unicode
- y — sticky
Python Essentials
Data Types
str, int, float, bool
list, tuple, dict, set
List Methods
append(), extend(), insert()
remove(), pop(), clear()
sort(), reverse(), copy()
String Methods
split(), join(), strip()
replace(), find(), startswith()
upper(), lower(), title()
Control Flow
if/elif/else
for item in iterable:
while condition:
try/except/finally
React Essentials
Hooks
useState(initialValue)
useEffect(() => {}, [])
useContext(Context)
useReducer(reducer, initial)
useMemo(() => {}, [deps])
useCallback(() => {}, [deps])
Component Patterns
function Component({props})
const [state, setState] = useState()
return <JSX />
Event Handling
onClick={handleClick}
onChange={e => setValue(e.target.value)}
onSubmit={handleSubmit}
Conditional Rendering
{condition && <Component />}
{condition ? <A /> : <B />}
GSAP Animation
Basic Tweens
gsap.to(target, {duration: 1, x: 100})
gsap.from(target, {opacity: 0})
gsap.fromTo(target, {x: 0}, {x: 100})
gsap.set(target, {opacity: 0})
Timeline
const tl = gsap.timeline()
tl.to(el, {x: 100})
tl.to(el2, {y: 50}, "<")
tl.play() / pause() / reverse()
Properties
x, y, rotation, scale
opacity, backgroundColor
width, height
ease: "power2.out"
ScrollTrigger
scrollTrigger: {
trigger: ".element",
start: "top 80%"
}
PHP Essentials
Syntax
<?php ... ?>
$variable = "value";
echo "Hello " . $name;
// Comment
Arrays
$arr = array(1, 2, 3);
$arr = [1, 2, 3];
$assoc = ["key" => "value"];
count(), array_push(), in_array()
Functions
function name($param) {
return $result;
}
strlen(), substr(), explode()
Superglobals
$_GET, $_POST, $_SESSION
$_COOKIE, $_SERVER
$_FILES, $GLOBALS
Git Commands
Basic Commands
git init
git clone <url>
git add . / git add <file>
git commit -m "message"
git push / git pull
Branching
git branch <name>
git checkout <branch>
git checkout -b <new-branch>
git merge <branch>
git branch -d <branch>
Status & History
git status
git log --oneline
git diff
git show <commit>
Docker Commands
Images
docker build -t <name> .
docker images
docker pull <image>
docker rmi <image>
Containers
docker run -p 3000:3000 <image>
docker ps / docker ps -a
docker stop <container>
docker rm <container>
docker exec -it <container> bash
Docker Compose
docker-compose up
docker-compose down
docker-compose build
docker-compose logs
HTTP Status Codes
2xx Success
- 200 OK
- 201 Created
- 204 No Content
3xx Redirect
- 301 Moved Permanently
- 302 Found
- 304 Not Modified
4xx/5xx Errors
- 400 Bad Request
- 401 Unauthorized
- 403 Forbidden
- 404 Not Found
- 500 Internal Server Error
HTML Codes (Entities)
Reference for printable characters in decimal 32–255, with HTML Number (e.g. ), HTML Name when available, and hex. Click any code to copy.
| Char | Dec | HTML Number | Name | Hex | Description |
|---|