PHP和JavaScrip分别获取关联数组的键值示例代码

$o = array('x'=>1, 'y'=>2, 'z'=>3); 
$arr = array(); 
$i = 0; 
foreach( $o as $arr[$i++]=>$v )/*empty*/; 
var_dump($arr); //$arr = array('x', 'y', 'z');

var o = {x:1, y:2, z:3}; 
var arr = [], i = 0; 
for ( arr[i++] in o ) /*empty*/ ; 
console.log( arr ); //arr = ['x', 'y', 'z'];