如何判断两个数组相等呢？其实很简单，用 == 或者 === 就可以了
php手册里说明如下：

那像 array('k'=>array())这样的多维数组能用如上方法判断相等吗？当然也可以。
若数组是数字索引的，就要注意一下了，见代码：
复制代码 代码如下:
<"apple", "banana");
$b = array(1 => "banana", "0" => "apple");

var_dump($a == $b); // bool(true)
var_dump($a === $b); // bool(false)
"codetitle">复制代码 代码如下:
<"a" => "apple", "b" => "banana");
$b = array("a" => "pear", "b" => "strawberry", "c" => "cherry");

$c = $a + $b; // Union of $a and $b
echo "Union of \$a and \$b: \n";
var_dump($c);

$c = array_merge($a, $b); // Union of $b and $a
echo "array_merge of \$b and \$a: \n";
var_dump($c);
"codetitle">复制代码 代码如下:
Union of $a and $b:
array(3) {
  ["a"]=>
  string(5) "apple"
  ["b"]=>
  string(6) "banana"
  ["c"]=>
  string(6) "cherry"
}
array_merge of $b and $a:
array(3) {
  ["a"]=>
  string(4) "pear"
  ["b"]=>
  string(10) "strawberry"
  ["c"]=>
  string(6) "cherry"
}