Detailed explanation of array_count_values() function in php

array array_count_values ​​(array $input)array_count_values() returns an array that uses the value in the input array as the key name and the number of times the value appears in the input array as the value. Count the number of occurrences of all values ​​in the array:

<?php
$a=array("A","Cat","Dog","A","Dog");
print_r(array_count_values($a));
?>

Definition and usage

array_count_values() function is used to count the occurrences of all values ​​in the array frequency.

Syntax

array_count_values(array)

Parameter Description

##array Required. Specifies an array that needs to count the occurrences of all values ​​in the array.

array_values()//可以剥离数组中的关联键和数值键，或得有其元素的值所组成的数组
  array_keys()//获得所有的关联键和数值键
 利用这两个函数就可以非常方便简单的实现
 array_count_values()函数
 思路就是先用array_values()或得元素值数组
 再将元素值数组作为关联键新建一个数组（当然得先检查该关联键是否存在）
 然后再用foreach循环原来的数组将元素值作为新数组的关联键操作即可
 可能表达的不是很清楚，直接上代码
 
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 <?php
     //统计数组中数据出现的频率   
      function  mycount($arr)    
          {        if(is_array($arr))      
                {           
                     $values = array_values($arr); //取得数组中数值                         
                     $count = array();//初始化数组                                      
                     foreach ($values as $value)            
                         {                
                             if(!array_key_exists($value,$count))                
                             {                    
                                 //如果键不存在则创建关联键                    
                                 $temp = array($value=>0);  //连接两个数组实际上相当于往里面添加元素                    
                                 $count=array_merge($count,$temp);                                   
                               }           
                           }            
                               foreach ($values as $key)           
                                {                
                                    $count[$key]++;           
                                 }            
                                 return $count;       
                              }       
                           return  $arr;     
                         }   
                          $a = array("ABC","FUCKYOU","ABC","Dady","PO","Dady","LIN","ABC","LIN","FUCKYOU");  
                          $a = mycount($a);    
                          print_r($a);    
   ?>    
   // 运行结果
   Array (    [ABC] => 3    [FUCKYOU] => 2    [Dady] => 2    [PO] => 1    [LIN] => 2 )

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