What are the components of a PHP function?

A PHP function usually contains: 1. Function name, starting with a letter or underscore; 2. Parameter list, defining the parameters received by the function; 3. Function body, including execution code; 4. Return value (optional), using return statement specified.

Component elements of PHP functions

PHP functions are code blocks that encapsulate specific operations or functions and can be reused to improve Code efficiency and maintainability. Typical elements of a PHP function include the following parts:

1. Function name

The function name identifies the uniqueness of the function and must start with a letter or underscore in PHP , the following characters can be letters, numbers or underscores.

2. Parameter list

The parameter list defines the parameters received by the function. The parameter type and number must be strictly adhered to when calling the function. Parameters are separated by commas and default values ​​can be specified.

3. Function body

The function body contains the code to be executed, usually enclosed in curly brackets {}. The code in the function body defines what the function does.

4. Return value (optional)

The function can return a value, specified using the return statement. If no return type is specified, the function returns null.

Practical case

For example, the following code defines a function named sum, which is used to calculate the sum of two numbers:

function sum($num1, $num2) {
  return $num1 + $num2;
}

The sum function can be called using the following code:

$result = sum(10, 20);

After that, the value of $result will be 30.

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