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PHP · Module 4 of 10

Functions and include files

Reuse code with functions and includes.

📖 Key ideas

  1. function greet(string $name): string { return "Hi $name"; }
  2. Default parameters and type declarations.
  3. include/require load other PHP files; require_once avoids duplicates.
  4. Organise code into reusable files.
  5. Built-in functions cover strings, dates, math and arrays.
💡 Real-life example: include is borrowing a chapter from another book instead of rewriting it.
functionDefines reusable code
require_onceIncludes a file once, fails if missing
Type declarationParameter/return types
Default parameterValue used when not passed