print_r

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Prints human-readable information about a variable

print_r ( mixed $expression [, bool $return = FALSE ] ) : mixed

expression

The expression to be printed.

return

If you would like to capture the output of print_r(), use the return parameter. When this parameter is set to TRUE, print_r() will return the information rather than print it.

If given a string, integer or float, the value itself will be printed. If given an array, values will be presented in a format that shows keys and elements. Similar notation is used for objects. When the return parameter is TRUE, this function will return a string. Otherwise, the return value is TRUE.

<? $expression = false; print_r($expression); ?>

<? $expression = 0; print_r($expression); ?>

0

<? $expression = 0.0; print_r($expression); ?>

0

<? $expression = "0"; print_r($expression); ?>

0

<? $expression = array(0, 1, array(0, 1)); print_r($expression); ?>

Array
(
    [0] => 0
    [1] => 1
    [2] => Array
        (
            [0] => 0
            [1] => 1
        )

)

<? $expression = new stdclass; $expression->var = 0; print_r($expression); ?>

stdClass Object
(
    [var] => 0
)

<? class myclass { public $var; } $expression = new myclass; $expression->var = 0; print_r($expression); ?>

myclass Object
(
    [var] => 0
)

<? class myclass { public $var; } $expression = new myclass; $expression->var = 0; $return = false; $output = print_r($expression, $return); echo "output: " . PHP_EOL . $output; ?>

myclass Object
(
    [var] => 0
)
output: 
1

<? class myclass { public $var; } $expression = new myclass; $expression->var = 0; $return = true; $output = print_r($expression, $return); echo "output: " . PHP_EOL . $output; ?>

output: 
myclass Object
(
    [var] => 0
)

var_dump

var_export

PHP