Explore the components of a PHP function

PHP functions include function declaration, parameter list, function body and return value type. They are used to encapsulate repeatable code blocks and improve code reusability. The parameter list specifies the parameter type and name, the function body contains the function code, and the return value type specifies the value type returned by the function. For example, the function "calculateCircleArea" that calculates the area of ​​a circle accepts a float argument $radius and returns a float.

Explore the components of PHP functions

Functions are structures in PHP that encapsulate repeatable blocks of code. They can improve Code reusability and readability. A PHP function consists of the following components:

• Function declaration (function declaration): Declare the function, specify the function name and parameter list.

function add(int $a, int $b): int
{
    return $a + $b;
}

• Parameter list (parameter list): Optional, specifies the parameter type and name passed to the function.
• Function body (function body): Contains the code of a function that performs the required calculation or operation.
• Return value type (return type): Optional, specifies the type of value returned by the function. If omitted, the function returns void.

Practical case: Calculating the area of ​​a circle

Consider a function that calculates the area of ​​a circle:

function calculateCircleArea(float $radius): float
{
    return pi() * $radius ** 2;
}

• Function declaration:calculateCircleArea, which accepts a floating point parameter $radius and returns a floating point type.
• Parameter list: $radius, indicating the radius of the circle.
• Function body: formula for calculating the area of ​​a circle pi() * radius**2.
• Return value type: float.

Calling a function

To call a function, you simply use the following syntax:

$result = add(1, 2);

Here, $result will contain the return value of the function call, in this case 3.

Type hinting

PHP 7 introduced type annotations, which allow you to explicitly specify the types of function parameters and return values. This helps catch type errors and improves code readability.

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