PHP Array实用函数参考

array_flip
交换数组中的键和值
$arr1 = array('a'=>1,'b'=>2,'c'=>3,'d'=>4);
$array = array_flip($arr1);
showArr($array);
/*
Array
(
[1] => a
[2] => b
[3] => c
[4] => d
)
*/
array_key_exists
 
检查给定的键名或索引是否存在于数组中(也可用于对象)
 
$arr1 = array('a'=>1,'b'=>2,'c'=>3,'d'=>4);
echo array_key_exists('b',$arr1); //1 (true)
 
array_keys
 
返回数组中所有的键名
$arr1 = array('a'=>1,'b'=>2,'c'=>3,'d'=>4,5);
$array = array_keys($arr1);
showArr($array);
/*
Array
(
[0] => a
[1] => b
[2] => c
[3] => d
[4] => 0
)
*/