How to query the number of occurrences of a string in php

Two methods to query the number of occurrences of a string: 1. Use the substr_count() function to calculate the number of times a specified substring appears in a string in a case-sensitive manner. The syntax "substr_count(string, search sub String, start search position, search length)". 2. Use the mb_substr_count() function to count the number of occurrences of a string. The syntax is "mb_substr_count (string, search substring, character encoding)".

The operating environment of this tutorial: windows7 system, PHP version 8.1, DELL G3 computer

php query string There are two functions for the number of occurrences

• substr_count() function

• mb_substr_count() function

Method 1: Use the substr_count() function to count the number of times

The substr_count() function counts the number of times a substring appears in a string (case-sensitive).

Syntax:

substr_count(string,substring,start,length)

• string Required. Specifies the string to be checked.

• #substring Required. Specifies the string to search for.​

• #start Optional. Specifies where in the string to begin the search.

• #length Optional. Specifies the length of the search.

Note: If the start parameter plus the length parameter is greater than the string length, this function generates a warning.

Example 1:

<?php
header("Content-type:text/html;charset=utf-8");
$str="I love Shanghai. Shanghai is the biggest city in china.";
echo "原字符串：".$str."<br>";
$count=substr_count($str,"Shanghai");
echo "Shanghai 出现了：".$count."次";
?>

Output result:

##Example 2:

<?php
header("Content-type:text/html;charset=utf-8");
$str="我爱上海。上海是中国最大的城市";
echo "原字符串：".$str."<br>";
$count=substr_count($str,"上海");
echo "上海  出现了：".$count."次";
?>

Method 2: Use the mb_substr_count() function to count the number of times

The mb_substr_count() function counts the number of times a string appears.

Syntax:

mb_substr_count(string,substring,encoding)

• string Required. Specifies the string to be checked.

• #substring Required. Specifies the string to search for.

• encoding is optional. Specifies the character encoding. If omitted or null, the internal character encoding is used.

<?php
header("Content-type:text/html;charset=utf-8");
$str="我爱上海。上海是中国最大的城市。";
echo "原字符串：".$str."<br>";
$count=mb_substr_count($str,"中国");
echo "中国 出现了：".$count."次";
?>

Output result:

<?php
header("Content-type:text/html;charset=utf-8");
$str="I love Shanghai. Shanghai is the biggest city in china.";
echo "原字符串：".$str."<br>";
$count1=mb_substr_count($str,"Shanghai");
echo "Shanghai 出现了：".$count1."次<br>";
$count2=mb_substr_count($str,"shanghai");
echo "shanghai 出现了：".$count2."次";
?>

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