Uncovering the makeup of PHP functions

PHP function consists of name, parameter list and function body. The name is a unique identifier for the function, the parameter list defines the parameters the function receives, and the function body contains the code to be executed. Parameters can be passed by value, by reference, or by default. Mastering functional components helps create reusable and maintainable code.

Uncovering the composition of PHP functions

PHP functions are reusable blocks of code in a program that perform specific tasks. They consist of a name, parameter list, and function body. Let’s take a closer look at the components of a PHP function:

Name

A function name is a unique identifier used to refer to a function. It should be short, descriptive, and follow PHP naming conventions.

Parameter list

The parameter list defines the parameters received by the function. Parameters can be passed by value, by reference, or by default.

Function body

The function body contains the code to be executed. It is usually enclosed in curly brackets ({}).

Practical case

The following is an example of defining a PHP function that sums two numbers:

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

In this example, sum is the function name, $num1 and $num2 are parameters passed by value, and the function body contains the code for summation.

Calling functions

You can call functions by passing parameters and storing them in variables:

$result = sum(5, 10);
echo $result; // 输出 15

Pass by value, by Pass-by-reference and default parameters

Parameters can be passed by value, by reference, or with default values.

• Pass by value: Pass a copy of the parameter, modifications in the function will not affect the original variable.
• Pass by reference: Pass a reference to the original variable, and modifications in the function will affect the original variable.
• Default parameters: If no parameters are provided when calling the function, the default value will be used.

By understanding the components of a function, you can create reusable and maintainable code.

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