php array_diff使用注意

 

$a1=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow");
$a2=array("e"=>"red","f"=>"green","g"=>"blue");

$result=array_diff($a1,$a2);
print_r($result);

实现的是 $a1 - $a2  如果要比较数组的一致性  还需要  $a2 - $a1