How to call custom PHP function via function pointer?

Function pointer is a data type in PHP, used to dynamically call functions without explicitly specifying the function name. To declare a function pointer, use the $functionPointer = 'function_name' syntax. To call a function pointer, use the call operator $functionPointer(). This is useful when function names are stored in variables or loaded dynamically.

How to call a custom PHP function through a function pointer

The function pointer is a special data type in PHP that stores Points to the memory address of other functions. Through function pointers, we can dynamically call functions without explicitly specifying the function name. This is useful in certain situations, such as when the function name is stored in a variable.

Syntax

To declare a function pointer, use the following syntax:

$functionPointer = 'function_name';

where $functionPointer is the function pointer variable , and function_name is the name of the function to be referenced.

Call function pointer

To call a function through a function pointer, use the call operator():

$functionPointer();

This The function stored in $functionPointer will be called.

Practical case

Suppose we have a custom function calculateArea(), used to calculate the area of ​​a rectangle:

function calculateArea(int $width, int $height): int
{
    return $width * $height;
}

Now, we can call this function through the function pointer:

$functionPointer = 'calculateArea';
$result = $functionPointer(5, 10); // 传入参数

echo $result; // 输出结果

This method is especially useful when the function name is stored in a variable or dynamically loaded from other modules.

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