Parameters and return values ​​of PHP functions

PHP function parameters can have type specifications and default values, and the return value can return a type specification value. For example, a function sum() that calculates the sum of two numbers and returns an integer takes two integer arguments, one of which has the default value "Guest".

Parameters and return values ​​of PHP functions

Function parameters

Function parameters is the data value passed to the function. They allow functions to perform specific tasks. Parameters appear as a comma-separated list in function definitions and function calls.

function function_name(parameter1, parameter2) {}

Parameter type description

Parameters can have type specifications. The type specification specifies the expected data type of the parameter.

function sumOfNumbers(int $num1, int $num2) {}

In this example, the sumOfNumbers() function expects two integer parameters ($num1 and $num2).

Default parameter values

Parameters can have default values. When a function is called, if a parameter value is specified, it is used. If not specified, the default value is used.

function greetUser($name = "Guest") {}

In this example, the greetUser() function has a default parameter $name with the value "Guest".

Return value

The function can return a value. The return value is the data value of the function execution result. The return value is specified using the return statement.

function function_name(): return_type {}

Return value type specification

The return value can have a type specification. The type specification specifies the expected data type of the return value.

function getSumOfNumbers(): int {}

In this example, the getSumOfNumbers() function returns an integer.

Practical Case

Consider a function that calculates the sum of two numbers:

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

// 调用函数
$result = sum(5, 10);

// 打印结果
echo $result; // 输出 15

The above is the detailed content of Parameters and return values ​​of PHP functions. For more information, please follow other related articles on the PHP Chinese website!