PHP print_r() Function

PHP 可用的函数PHP Available Functions

print_r()The function is used to print a variable in a more readable form.

PHP Version Requirements: PHP 4, PHP 5, PHP 7

Syntax

bool print_r ( mixed $expression [, bool $return ] )

Parameter Description:

  • $expression: The variable to be printed. If it is a string, integer, or float type variable, the variable value itself will be printed. If it is an array, the keys and elements will be displayed in a certain format. Objects are similar to arrays.
  • $return: Optional. If true, the result is not output, but assigned to a variable; if false, the result is output directly.

Return Value

$returnIf set totrueThere is a return value, which is an easy-to-understand string message.

Example

Example

<?php $a = array ('a' => 'apple', 'b' => 'banana', 'c' => array ('x','y','z')); print_r ($a); ?>

The output result is:

Array
(
    [a] => apple
    [b] => banana
    [c] => Array
        (
            [0] => x
            [1] => y
            [2] => z
        )

)

Set$returnParameter:

Example

<?php $b = array ('m' => 'monkey', 'foo' => 'bar', 'x' => array ('x', 'y', 'z')); $results = print_r ($b, true); //$results contains the output result of print_r ?>

The above information has no output because the output result was assigned to$resultsvariable.

PHP 可用的函数PHP Available Functions

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