Home  >  Article  >  Backend Development  >  What are the rules for the return value of a custom PHP function?

What are the rules for the return value of a custom PHP function?

PHPz
PHPzOriginal
2024-04-22 22:03:01321browse

Return value rules for custom PHP functions: All functions must return a value (can be NULL). Use the return keyword or implicitly return the last expression value. The return value must be the value itself, not a reference.

自定义 PHP 函数的返回值有什么规定?

The return value of a custom PHP function: rules and practice

In PHP, the return value of a custom function follows certain rules Rules to ensure code maintainability and predictability.

Rules:

  • All functions must return a value, and the type can be any valid data type (including NULL).
  • If a function does not explicitly return a value, it will return NULL by default.
  • You can use the return keyword to return a value, or you can have the function implicitly return the value of the last expression.
  • The return value cannot be a reference, it must be the value itself.

Practical case:

Create a custom function calculateSum(), which calculates the sum of two numbers:

<?php
function calculateSum($num1, $num2) {
    $sum = $num1 + $num2;
    return $sum; // 显式地返回和
}

// 使用函数
$result = calculateSum(5, 10);
echo "The sum is: $result"; // 输出 15
?>

In this example, the function calculateSum() returns the calculated sum of type int. It uses the return keyword to explicitly specify the return value.

Note:

  • Ensure that the function correctly handles all possible input scenarios, including invalid inputs and boundary conditions.
  • Clearly specify return value types in documentation to improve code readability and maintainability.
  • Following these rules is critical to writing clean, reusable, and maintainable PHP functions.

The above is the detailed content of What are the rules for the return value of a custom PHP function?. For more information, please follow other related articles on the PHP Chinese website!

Statement:
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn