PHP
The classic server-side scripting language.
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This course has 4 lessons. Start with the first one and use the next / previous links at the bottom of each lesson — the sidebar keeps the whole course in order.
Lessons
- PHP: getting startedHow PHP runs on the server, mixing code with HTML, and the request/response model behind almost every classic website.
- PHP variables and stringsDynamic typing, interpolation, heredoc, and the loose-comparison quirks that cause real security bugs.
- PHP arraysOne type for lists and maps, the array functions worth knowing, and array_map/filter across collections.
- Forms, sessions and safetyHandling GET and POST, validating input, keeping sessions, and the defences against the classic web attacks.
More in Back-end Development
Last refreshed 2026-09-17.