Detailed explanation of how to use php function to intercept string instances

This article mainly introduces the usage analysis of phpString interception function, and gives two examples, respectively describing the usage of PHP's own string interception function and custom function The method of realizing string interception is a very practical string operation skill.

This article analyzes the usage of php string interception function with examples. Share it with everyone for your reference. The specific analysis is as follows:

The function that comes with PHP to intercept strings can only handle English, but it cannot intercept numbers that are mixed in Chinese. The latter example is easier to use, and the first one is mainly for beginners to learn. Used, the specific code is as follows:

<?php 
  //构造字符串 
  $str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; 
  echo "原字符串：<b>".$str."</b><br>"; 
  //按各种方式进行截取 
  $str1 = substr($str,5); 
  echo "从第5个字符开始取至最后：".$str1."<br>"; 
  $str2 = substr($str,9,4); 
  echo "从第9个字符开始取4个字符：".$str2."<br>"; 
  $str3 = substr($str,-5); 
  echo "取倒数5个字符：".$str3."<br>"; 
  $str4 = substr($str,-8,4); 
  echo "从倒数第8个字符开始向后取4个字符：".$str4."<br>"; 
  $str5 = substr($str,-8,-2); 
  echo "从倒数第8个字符开始取到倒数第2个字符为止：".$str5."<br>"; 
 ?>

supports mixed Chinese and English interception, the code is as follows:

<?php 
/* 
------------------------------------------------------ 
参数： 
$str_cut    需要截断的字符串 
$length     允许字符串显示的最大长度 
 
程序功能：截取全角和半角（汉字和英文）混合的字符串以避免乱码 
------------------------------------------------------ 
*/ 
function substr_cut($str_cut,$length) 
{
    if (
strlen
($str_cut) > $length) 
    {  
        for($i=0; $i < $length; $i++)  
        if (ord($str_cut[$i]) > 128)    $i++;  
        $str_cut = substr($str_cut,0,$i)."..";  
    }  
    return $str_cut;  
} 
?>

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