PHP 自定义方法实现数组合并

$ar1    = array("color" => array("favorite" => "red","name"=>"test"));
$ar2    = array("color" => array("favorite" => "green","code"=>"code"));
print_r (array_merge ($ar1, $ar2));
print_r(array_merge_recursive ($ar1, $ar2));

/**
 * @Author:     -HTL
 * @Email:       Huangyuan413026@163.com
 * @DateTime:    2016-04-21 12:01:51
 * @Description: 根据指定的健名将$ar2中的所有健值复制到$ar1对应的健值中
 * @Return：$ar1
 */
 function array_more_merge($ar1,$ar2,$key_name){
    if(
        !$ar1 
        || !is_array($ar1) 
        || count($ar1)<=0
        || !$ar2
        || !is_array($ar2) 
        || count($ar2)<=0
        || !$key_name 
        || strlen($key_name)<=0)
    {
        return $ar1;
    }
    //不能使用for进行循环,因为如果数组中的索引不是连续的则使用for可能无法正确的完成循环
    //如 $a = 
           Array(
            1 => Array("id" => 1 )
           ,8 => Array("id" => 2 )
           ,4 => Array("id" => 4 )
          );
    //该数组数为3所以只能找到[1],而[8][4]在循环中不会进行处理,因为$i <=count($a)不成立
    for ($i=0; $i <=count($a) ; $i++) { 
            print_r($a[$i]);
    }
    foreach ($ar1 as $i=>$items) {
        foreach ($ar2 as $key=>$item) {
            if($ar2[$key][$key_name]==$ar1[$i][$key_name]){
                $keys = array_keys($ar2[$key]);
                foreach ($keys as $name) {
                    $ar1[$i][$name] = $ar2[$key][$name];
                }
            }
        }
    }
    return $ar1;
} 
$ar1 = ‘{"1":{"cost":"1","id":"1","total_price":"5"},"2":{"cost":"2","id":"2","total_price":"10"},"4":{"cost":"4","id":"4","total_price":"20"}}‘;
$ar1 = json_decode($ar1,true);
$ar2 = ‘{"1":{"cost":"1","id":"1","total_price":"5"},"2":{"cost":"20","id":"2","total_price":"100"},"4":{"cost":"40","id":"4","total_price":"200"}}‘;
$ar2 = json_decode($ar2,true);
echo "array_merge_recursive:";
print_r(array_merge_recursive($ar1,$ar2));
echo "array_merge:";
print_r(array_merge($ar1,$ar2));
echo "array_more_merge:";
print_r($this->array_more_merge($ar1,$ar2,"id"));
die();