QUICK REFERENCE
Developer Cheatsheets
Essential syntax and properties for the modern full-stack developer. Bookmark this page for quick access during projects.
HTML
Structure
<html>
<head>
<body>
<header>
<main>
<footer>
Content
<h1> - <h6>
<p>
<a>
<img>
<ul>/<li>
<div>
<span>
Forms
<form>
<input>
<textarea>
<button>
<label>
<select>
CSS
Selectors
.class
#id
element
element > child
:hover
:not()
Layout
display: flex
display: grid
position: relative/absolute
z-index
Flexbox
flex-direction
justify-content
align-items
gap
flex-wrap
JavaScript
Basics
let/const
function() {}
=> arrow func
if/else
for/while
DOM
document.getElementById()
querySelector()
addEventListener()
classList
Async
fetch()
async/await
Promise
then/catch
setTimeout()
PHP
Basics
$variable
echo
include/require
foreach
function
Superglobals
$_GET
$_POST
$_SESSION
$_COOKIE
$_SERVER
Database
PDO
prepare()
execute()
fetch()
fetchAll()
SQL
CRUD
SELECT
INSERT INTO
UPDATE
DELETE
Clauses
WHERE
ORDER BY
LIMIT
JOIN
GROUP BY
Functions
COUNT()
SUM()
AVG()
MAX()/MIN()