PHP中文网

相同点：array_diff_assoc和array_diff均只包含仅仅出现在$array1中的数组元素
不同点：array_diff_assoc比较的时候，会同时比较数组对应的key是否相同，而array_diff不比较key
如果要实现真正意义上的两个数组差异比较，见后边网友提供的arr_diff()函数，用递归方式实现

详细见代码说明：
<?php
$array1 = array (”a” => “green”, “b” => “brown”, “c” => “blue”, “red”,’d'=>’good’);
$array2 = array (”a” => “green”, “yellow”, “red”,’good’);
$result_assoc = array_diff_assoc($array1, $array2);

$result_diff = array_diff($array1, $array2);

echo “array1=\r\n”;
print_r($array1);
echo “\r\narray2=\r\n”;
print_r($array2);
echo “\r\n\r\n”;
print_r($result_assoc);

echo “\r\narray_diff:\r\n”;
print_r($result_diff);
?>
结果：
array1=
Array
(
[a] => green
=> brown
[c] => blue
[0] => red
[d] => good
)

array2=
Array
(
[a] => green
[0] => yellow
[1] => red
[2] => good
)
Array
(
=> brown
[c] => blue
[0] => red
[d] => good
)

array_diff:
Array
(
=> brown
[c] => blue
)

附ottodenn at gmail dot com写的函数：

<?php
function arr_diff($a1,$a2){
$ar = array();
foreach ($a2 as $k => $v) {
if (!is_array($v)) {
if ($v !== $a1[$k])
$ar[$k] = $v;
}else{
if ($arr = arr_diff($a1[$k], $a2[$k]))
$ar[$k] = $arr;
}
}
return $ar;
}

// example:

$arr1 = array(
‘user1′ => array(
‘name’ => ‘john d.’,
’street’ => ‘elmstreet no. 2′,
‘city’ => ‘berlin’
),
‘user2′ => array(
‘name’ => ‘harald c.’,
’street’ => ‘b-street no. 7′,
‘city’ => ‘cologne’
)
);
$arr2 = array(
‘user1′ => array(
‘name’ => ‘john b.’, // change #1
’street’ => ‘elmstreet no. 2′,
‘city’ => ‘berlin’
),
‘user2′ => array(
‘name’ => ‘harald c.’,
’street’ => ‘b-street no. 7′,
‘city’ => ‘bavaria’ // change #2
)
);
print_r(arr_diff($arr1, $arr2));

/*
will output:

Array
(
[user1] => Array
(
[name] => john b.
)

[user2] => Array
(
[city] => bavaria
)

)

*/

?>