PHP数组的交集array_intersect(),array_intersect_assoc(),array_inter_key()函数的小问题

　　求两个数组的交集问题可以使用array_intersect(),array_inersect_assoc,array_intersect_key来实现，其中array_intersect()函数是求两个数的交集，返回一个交集共有元素的数组（只是数组值得比较）、array_intersect_assoc()函数是将键值和值绑定，一起比较交集部分、array_intersect_key()函数是将两个数组的键值进行比较，返回键值交集的数组。

　　但实际应用中也遇到了一些小问题，正如下：

　　实例：

  

    
   <?
   PHP
 
   $array
    
   =
    
   array
   (
   "
   red
   "
   =>
   "
   Red
   "
   ,
   "
   green
   "
   =>
   "
   red4
   "
   ,
   "
   Red15
   "
   =>
   "
   Red
   "
   ,
   7
   =>
   "
   Level
   "
   ,
   "
   Width
   "
   =>
   "
   Red
   "
   ,
   "
   azzzz1
   "
   =>
   "
   art
   "
   ,
   "
   peak
   "
   =>
   158
   );
 
   $array1
    
   =
    
   array
   (
   "
   red
   "
   =>
   "
   Red2
   "
   ,
   "
   greena
   "
   =>
   "
   red
   "
   ,
   "
   Red15
   "
   =>
   "
   Red
   "
   ,
   7
   =>
   "
   Level
   "
   ,
   "
   Width
   "
   =>
   "
   Red
   "
   ,
   "
   azzzz
   "
   =>
   "
   art
   "
   ,
   "
   peak
   "
   =>
   158
   );
 
   $num
    
   =
    
   array_intersect
   (
   $array
   ,
   $array1
   );
 
   print_r
    (
   $num
   );
 
   echo
    
   "
   <br />
   "
   ;
 
   $num
    
   =
    
   array_intersect_assoc
   (
   $array
   ,
   $array1
   );
 
   print_r
   (
   $num
   );
 
   echo
    
   "
   <br />
   "
   ;
 
   $num
    
   =
    array_intersect_key(
   $array
   ,
   $array1
   );
 
   print_r
    (
   $num
   );

 
   ?>
  

　　运行结果：

   

    Array
     ( [red] 
    =>
     Red [Red15] 
    =>
     Red [
    7
    ] 
    =>
     Level [Width] 
    =>
     Red [azzzz1] 
    =>
     art [peak] 
    =>
     
    158
     ) 

    Array
     ( [Red15] 
    =>
     Red [
    7
    ] 
    =>
     Level [Width] 
    =>
     Red [peak] 
    =>
     
    158
     ) 

    Array
     ( [red] 
    =>
     Red [Red15] 
    =>
     Red [
    7
    ] 
    =>
     Level [Width] 
    =>
     Red [peak] 
    =>
     
    158
     )
   

　　总结：

　　　　1.array_intersect()函数进行的比较只有数组值的比较，而且存在如”Red“和”Red2“比较时会返回"Red"，反之则不会返回"Red2";

　　　　2.array_intersect_assoc()函数是将数组的值与键值一起比较，而且不会存在array_intersect的情况，适用于较严格的比较；

　　　　3.array_intersect_key()函数适用于比较两个数组键值的交集，返回的并不只有键值，而是键值和对应的数组值。