PHP method to count the number of occurrences of all characters in a string

This article mainly introduces PHP's method of counting the number of occurrences of all characters in a string, involving operating techniques related to PHP character traversal and statistical operations. Friends in need can refer to the following

The examples in this article are described PHP implements a method to count the number of occurrences of all characters in a string. Share it with everyone for your reference, the details are as follows:

Let’s take a look at the effect first:

Algorithm:

Loop through the string once ($str in this example) and record the strings that have appeared in an array (such as this In the example $strRecord), if this recording function already exists, it will not be recorded;

is used to compare each string with the value of the record array (in this example $strRecord[]['key']), if a value in the record is the same as this string, record the number of times + 1 ($strRecord[]['count in this example ']);

Of course, set a variable, the default is false (such as $found in this example), record each comparison, if the record array already has this value , set it to true, and use this tag to record the array that has not been encountered into the array

Implementation code:

<?php
//统计字符串中出现的字符，出现次数
echo &#39;<pre class="brush:php;toolbar:false">&#39;;
$str = &#39;aaabbccqqwweedfghhjffffffffggggggggg&#39;;//字符串示例
echo $str.&#39;<br/>&#39;;
$strRecord=array();//把出现过的字符记录在此数组中，如果记录有，则不记录，
for($i=0;$i<strlen($str);$i++){
 $found = 0;//默认设置为没有遇到过
 foreach((array)$strRecord as $k=>$v){
  if($str[$i] == $v[&#39;key&#39;]){
   $strRecord[$k][&#39;count&#39;] += 1;//已经遇到，count + 1；
   $found = 1;//设置已经遇到过的，标记
   continue;//如果已经遇到，不用再循环记录数组了，继续下一个字符串比较
  }
 }
 if(!$found){
  $strRecord[] = array(&#39;key&#39;=>$str[$i],&#39;count&#39;=>1);//记录没有遇到过的字符串
 }
}
print_r($strRecord);
?>

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