PHP function to get the number of occurrences of a string in a file

This article will give you an example of how to get the number of occurrences of a string with substr_count() in PHP, and share it with you for your reference!

substr_count() in PHP can be used to count the number of occurrences of a substring in a specified string.

substr_count()The function is defined as follows:

substr_count(string,substring,start,length)

Parameter description:

string     必需。规定被检查的字符串。
substring  必需。规定要搜索的字符串。
start      可选。规定在字符串中何处开始搜索。
length     可选。规定搜索的长度。

Example:

<?php
 $str="脚本之家提供大量脚本代码及脚本特效下载";
 echo substr_count($str,"脚本");
 echo "<br/>";
 echo substr_count($str,"脚本",16);//指定在第16个字符后开始搜索
 echo "<br/>";
 echo substr_count($str,"脚本",16,10);//指定从第16个字符开始往后搜索10个字符结束
?>

Running results;

3
2
1

More examples:

1. Use all parameters

<?php
$str = "This is nice";
echo strlen($str)."<br>"; // 使用 strlen() 来返回字符串长度
echo substr_count($str,"is")."<br>"; // 字符串中 "is" 出现的次数
echo substr_count($str,"is",2)."<br>"; // 字符串缩减为 "is is nice"
echo substr_count($str,"is",3)."<br>"; // 字符串缩减为 "s is nice"
echo substr_count($str,"is",3,3)."<br>"; // 字符串缩减为 "s i"
?>

2. Overlapping substrings

<?php
$str = "abcabcab";
echo substr_count($str,"abcab"); // 此函数不会对重叠的子字符串计数
?>

3. If the start and length parameters exceed the string length, output a warning

<?php
echo $str = "This is nice";
substr_count($str,"is",3,9);
?>

because of the length The value exceeds the length of the string (3 9 is greater than 12), and a warning will be output.

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