How to create and use custom functions in PHP
Functions in PHP are a great way to organize and modularize your code. In addition to the built-in functions, PHP allows you to create your own custom functions. This provides greater flexibility and reusability in your code.
Syntax
To create a custom function in PHP, use the function keyword followed by the function name, parameter list, and function body block, like this:
function functionName(parameter1, parameter2, ...) {
// function body
}
Usage Examples
Here are some examples of how to create and use custom functions in PHP:
Example 1: Simple function that returns the sum of two numbers
function sum($num1, $num2) {
return $num1 + $num2;
}
echo sum(2, 3); // Output: 5
Example 2: Function that calculates the factorial of a number
function factorial($num) {
if ($num == 0 || $num == 1) {
return 1;
} else {
return $num * factorial($num - 1);
}
}
echo factorial(5); // Output: 120
Parameter Values
| Parameter | Description |
|---|---|
| functionName | The name of the function you want to define. |
| parameter1, parameter2, … | The parameters for the function. |
| // function body | The actual code or statements that the function executes. |
Technical Details
| Property | Value |
|---|---|
| Supported | PHP version 4 and later. |
| Returns | Value specified in the function using the return statement, or NULL if no return value is specified. |
| Scope | Functions defined inside a class become methods of that class and have access to all the class members (methods and properties). |
For more information on custom functions in PHP, please visit the official PHP documentation.
Written by: Maria Jensen 24-05-2023 Written in: PHP tutorials