print_r() displays information
about a variable 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.
提示: 任何直接把輸出到瀏覽器的結果,可使用輸出控制函數來擷取 此函數的輸出,在將之存入一個 字串(舉例說明)。
pre ?php $a = array ('a' = 'apple', 'b' = 'banana', 'c' = array ('x','y','z')); print_r ($a); ? /pre |
Which will output:
pre Array ( [a] = apple [b] = banana [c] = Array ( [0] = x [1] = y [2] = z ) ) /pre |
注: 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.
See also ob_start(),
var_dump(), and var_export().