Implementation examples of simple intersection, difference and union functions of PHP arrays

<?php
$arr1 = array(
&#39;0&#39; => &#39;zero&#39;,
&#39;1&#39; => &#39;one&#39;,
&#39;2&#39; => &#39;two&#39;,
&#39;3&#39; => &#39;three&#39;
);
$arr2 = array(
&#39;2&#39; => &#39;two&#39;,
&#39;three&#39; => &#39;three&#39;,
&#39;4&#39; => &#39;four&#39;,
&#39;5&#39; => &#39;five&#39;
);
//差集【对比返回在 arr1 中但是不在 arr2 及任何其它参数数组中的值。】
$array_diff = array_diff($arr1,$arr2); 
echo "<pre class="brush:php;toolbar:false">"; print_r($array_diff);
/* 输出结果
*Array
*(
* [0] => zero
* [1] => one
*)
*/
//交集【对比返回既在 arr1 中也在 arr2 数组中的值。】
# 注意事项: 键值保留arr1数组中的键值不变
$array_intersect = array_intersect($arr1,$arr2); 
echo "<pre class="brush:php;toolbar:false">"; print_r($array_intersect);
/* 输出结果
*Array
*(
* [2] => two
* [3] => three
*)
*/
//并集【将arr1数组中的值附加在arr2数组的后面。返回作为结果的数组。 】
#注意事项：【如果输入的数组中有相同的字符串键名，则该键名后面的值将覆盖前一个值。
#然而，如果数组包含数字键名，后面的值将不会覆盖原来的值，而是附加到后面。】
$array_merge = array_merge($arr1,$arr2); 
echo "<pre class="brush:php;toolbar:false">"; print_r($array_merge);
/* 输出结果
* Array
* (
* [0] => zero
* [1] => one
* [2] => two
* [3] => three
* [4] => two
* [three] => three
* [5] => four
* [6] => five
* )
*/
?>