Print_r and var_dump output arrays in PHP, print_rvar_dump

Print_r and var_dump output arrays in PHP, print_rvar_dump

Print_r () and var_dump () functions can print the entire array content and structure.

Print_r ()

The print_r () function can be used to print the content and structure of the entire array and display keys and elements in a certain format. Note that the print_r () function is used not only for printing, but also for printing easy-to-understand information about variables.

Syntax:

Bool print_r (mixed expression) Example:

<?php$arr_age = array(18, 20, 25);print_r($arr_age);?>

Run the sample output:

Array ([0] => 18 [1] => 20 [2] => 25) view the webpage source code of the output result. You can see the easier-to-read format:

Array(  [0] => 18  [1] => 20  [2] => 25) var_dump()

Like the print_r () function, the var_dump () function can also be used to print the data and structure of an array. However, the var_dump () function is more powerful than print_r (). It can print multiple variables at the same time and provide the type information of the variables.

Example:

<?php$arr_age = array(18, 20, 25);var_dump($arr_age);?>

Run the sample output:

array(3) { [0]=> int(18) [1]=> int(20) [2]=> int(25)}

Print_r () and var_dump () functions are generally used for debugging programs. In more cases, echo is used to output specific array unit values.

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