Funções para Manipulação de variáveis
PHP Manual

print_r

(PHP 4, PHP 5)

print_r Prints human-readable information about a variable

Descrição

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

print_r() displays information about a variable in a way that's readable by humans.

print_r(), var_dump() and var_export() will also show protected and private properties of objects with PHP 5. Static class members will not be shown.

Remember that print_r() will move the array pointer to the end. Use reset() to bring it back to beginning.

Parâmetros

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.

Valor Retornado

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 object s.

When the return parameter is TRUE, this function will return a string . Otherwise, the return value is TRUE.

Notas

Nota: Esta função usa o interno buffer de saída com este parâmetro, então assim não pode ser usado dentro de uma função de callback para ob_start().

Histórico

Versão Descrição
4.3.0 The return parameter was added. If you need to capture the output of print_r() with an older version of PHP prior, use the output-control functions.
4.0.4 Prior to PHP 4.0.4, print_r() will continue forever if given an array or object that contains a direct or indirect reference to itself. An example is print_r($GLOBALS) because $GLOBALS is itself a global variable that contains a reference to itself.

Exemplos

Exemplo #1 print_r() example

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

O exemplo acima irá imprimir:

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

Exemplo #2 return parameter example

<?php
$b 
= array ('m' => 'monkey''foo' => 'bar''x' => array ('x''y''z'));
$results print_r($btrue); // $results now contains output from print_r
?>

Veja Também


Funções para Manipulação de variáveis
PHP Manual