(PHP 4 >= 4.0.0)

print_r --  Prints human-readable information about a variable


void print_r (mixed expression)

This function displays information about the values of variables in a way that's readable by humans. 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.

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

Tip: As with anything that outputs its result directly to the browser, you can use the output-control functions to capture the output of this function, and save it - for example - in a string.

Compare print_r() to var_dump().

$a = array (1, 2, array ("a", "b", "c"));
print_r ($a);


This function will continue forever if given an array or object that contains a direct or indirect reference to itself or that contains an array or object on a deeper level that does so. This is especially TRUE for print_r($GLOBALS), as $GLOBALS is itself a global variable and contains a reference to itself as such.