var_dump:打印变量的相关信息,包括该变量的类型和值
比如
<?php
$a = array(1, 2, array("a", "b", "c"));
var_dump($a);
?>
以上例程会输出:
array(3) {float(3.1)
bool(true)
[0]=> int(1) [1]=> int(2) [2]=> array(3) { [0]=> string(1) "a" [1]=> string(1) "b" [2]=> string(1) "c" }}
?>
以上例程会输出:
var_export:输出或返回一个变量的字符串表示,和var_dump()类似,不同的是其返回的合法的php代码如:
<?php
$b = 3.1;
$c = true;
var_dump($b, $c);
<?php
$a = array (1, 2, array ("a", "b", "c"));
var_export ($a);
/* 输出:
array (
0 => 1,
1 => 2,
2 =>
array (
0 => 'a',
1 => 'b',
2 => 'c',
),
)
*/
$b = 3.1;
$v = var_export($b, TRUE);
echo $v;
<?php
$a = array ('a' => 'apple', 'b' => 'banana', 'c' => array ('x','y','z'));
print_r ($a);
?>
/* 输出:3.1*/?>
print_r:打印变量易于理解的信息
<?php
$a = array ('a' => 'apple', 'b' => 'banana', 'c' => array ('x','y','z'));
print_r ($a);
?>
以上代码将输出:
Array
(
[a] => apple
[b] => banana
[c] => Array
(
[0] => x
[1] => y
[2] => z
)
)