(PHP 4, PHP 5)
print_r — Prints human-readable information about a variable
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.
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.
Informacja:
Ta funkcja używa wewnętrznie buforowania wyjścia, więc nie może być użyta wewnątrz funkcji callback podanej w wywołaniu ob_start().
| Wersja | Opis |
|---|---|
| 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. |
Przykład #1 print_r() example
<pre>
<?php
$a = array ('a' => 'apple', 'b' => 'banana', 'c' => array ('x', 'y', 'z'));
print_r ($a);
?>
</pre>
Powyższy przykład wyświetli:
<pre>
Array
(
[a] => apple
[b] => banana
[c] => Array
(
[0] => x
[1] => y
[2] => z
)
)
</pre>
Przykład #2 return parameter example
<?php
$b = array ('m' => 'monkey', 'foo' => 'bar', 'x' => array ('x', 'y', 'z'));
$results = print_r($b, true); // $results now contains output from print_r
?>