CodePrimer
Search a living directory of web syntax. Pick a problem, copy a working sample, then adapt it.
JavaScript
Beginner
Live input event
How do I react as the user types?
JavaScript
Beginner
change event on select
How do I detect dropdown changes?
HTML
Beginner
Radio button group
How do I let users pick only one option?
HTML
Beginner
Checkboxes as PHP arrays
How do I submit multiple checkboxes to PHP?
JavaScript
Beginner
Read input/select/textarea values
How do I read form field values in JS?
HTML
Beginner
Select dropdown
How do I make a dropdown menu?
HTML
Beginner
Textarea multi-line input
How do I collect long comments?
HTML
Beginner
Date, hidden, and file inputs
What special input types should I know?
HTML
Beginner
GET vs POST forms
When should a form use GET or POST?
JavaScript
Beginner
Block empty form fields in JS
How do I stop submit when a field is blank?
HTML
Beginner
Explicit label for= binding
How do I connect a label to an input?
PHP
Beginner
Read $_GET values
How do I read query string data?
PHP
Beginner
Read $_POST values
How do I read POST body fields?
PHP
Intermediate
Sanitize and validate input
How do I protect against XSS and bad emails?
PHP
Beginner
Read checkbox array in PHP
How do I read skills[] from a form?
PHP
Beginner
Detect GET vs POST in PHP
How do I know which HTTP method was used?