PHP functions for debug output:
differences between PHP var_dump vs print_r vs var_export:
var_dump is for debugging purposes. The var_dump function displays structured information about variables/expressions including its type and value. Arrays are explored recursively with values indented to show structure. It also shows which array values and object properties are references.
// var_dump(array('', false, 42, array('42')));
array(4) {
[0]=> string(0) ""
[1]=> bool(false)
[2]=> int(42)
[3]=> array(1) {[0]=>string(2) "42")}
}
print_r is for for debugging purposes, too, but does not include the member's type. It's a good idea to use if you know the types of elements in your array, but can be misleading otherwise. The print_r() displays information about a variable in a way that's readable by humans. array values will be presented in a format that shows keys and elements. Similar notation is used for objects.
Array (
[0] =>
[1] =>
[2] => 42
[3] => Array ([0] => 42)
)
var_export prints valid php code. Useful if you calculated some values and want the results as a constant in another script. Note that var_export can not handle reference cycles/recursive arrays, whereas var_dump and print_r check for these.
array ( 0 => '', 2 => false, 2 => 42, 3 => array (0 => '42',), )