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HomeBackend DevelopmentPHP TutorialWhat are the types of return values ​​​​of PHP functions?

PHP functions can return multiple types of values: no return value, primitive type, array, object, resource. Using type hints (such as : int) to specify the return value type ensures that the function returns the expected type, improving code reliability and maintainability.

PHP 函数返回值的类型有哪些?

The type of value returned by PHP function

PHP function can return different types of values, including:

  • No return value (void)
  • Primitive type(int, float, string, bool)
  • Array
  • Object
  • Resource

To specify the return value type of a function, use the following before the function name One of type hints:

  • int
  • float
  • string
  • bool
  • array
  • object
  • resource

Practical case

The following function gets the number of lines of the specified file and returns an integer:

function get_line_count(string $filename): int
{
    $file = fopen($filename, 'r');
    $lines = 0;

    while (!feof($file)) {
        fgets($file);
        $lines++;
    }

    fclose($file);

    return $lines;
}

This function uses : int type hint, indicating that it will return an integer. The code then uses fopen() to open the file and read it line by line, while incrementing the $lines count. Finally, it returns the value of $lines.

Using type hints can help ensure that functions return values ​​of the expected type, thereby improving the reliability and maintainability of your code.

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