Introduction to PHP method of replacing some characters in a string_PHP Tutorial

We will all use the str_replace function to replace strings in php. This function can also use regular expressions. The following editor will introduce to you an example of replacing some characters in a string or replacing the first appearing character.

Now there is a requirement: string A and string B. String B contains string A. Use string A to replace A in string B with other strings or delete it.

Using PHP functions, str_ireplace() and str_replace() can do this.

1. The str_ireplace(find,replace,string,count) function uses a string to replace other characters in the string (this function is not case-sensitive).

For example:

The code is as follows

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代码如下 复制代码 header(“Content-Type: text/html; charset=utf-8"); // 防止中文乱码 $str_1 = '郭g碗w瓢p盆p'; $str_2 = '?潘?'; $str_3 = 'PHP 替换字符串中的一些字符串-郭G碗w瓢p盆P'; $str = str_ireplace($str_1,$str_2,$str_3); echo $str; // 输出:PHP 替换字符串中的一些字符串-?潘 ?> header("Content-Type: text/html; charset=utf-8"); // Prevent Chinese garbled characters $str_1 = 'Guo g bowl w ladle p basin p'; $str_2 = '?Pan?'; $str_3 = 'PHP replace some strings in the string-Guo G bowl w ladle p basin P';                                                                                    $str = str_ireplace($str_1,$str_2,$str_3); 代码如下 复制代码 header(“Content-Type: text/html; charset=utf-8"); // 防止中文乱码 $str_1_s = '郭g碗w瓢p盆p'; $str_1_b = '郭G碗w瓢p盆P'; $str_2 = '?潘?'; $str_3 = 'PHP 替换字符串中的一些字符串-郭G碗w瓢p盆P'; $str_s = str_replace($str_1_s,$str_2,$str_3).' ';     $str_b = str_replace($str_1_b,$str_2,$str_3);     echo $str_s; // 无法查找到，输出原字符串     echo $str_b; // 被正确替换     // $str_s 输出:PHP 替换字符串中的一些字符串-郭G碗w瓢p盆P     // $str_b 输出:PHP 替换字符串中的一些字符串-?潘 ?> echo $str; // Output: PHP replaces some strings in the string -?Pan ?> 2. The str_replace(find,replace,string,count) function uses a string to replace other characters in the string (this function is case-sensitive). (Parameters and descriptions are the same as str_ireplace() function) The code is as follows Copy code  代码如下 复制代码 $str=preg_replace('/abc/','xyz',$str,1); echo $str; header("Content-Type: text/html; charset=utf-8"); // Prevent Chinese garbled characters $str_1_s = 'Guo g bowl w ladle p basin p'; $str_1_b = 'Guo G bowl w ladle p basin P'; $str_2 = '?Pan?'; $str_3 = 'PHP replace some strings in the string-Guo G bowl w ladle p basin P';                                                                       $str_s = str_replace($str_1_s,$str_2,$str_3).' '; $str_b = str_replace($str_1_b,$str_2,$str_3); echo $str_s; // Unable to find, output the original string echo $str_b; // Correctly replaced // $str_s output: PHP replaces some strings in the string - Guo G bowl w ladle p basin P // $str_b output: PHP replaces some strings in the string -?Pan ?>

If you want to replace the above, you must replace all the characters. What if I want to replace only the characters that appear for the first time? Many people have thought of using the str_replace() function to see if the use of this function is what we want str_replace( mixed $search , mixed $replace , mixed $subject [, int &$count ] ) I accidentally thought that was what we wanted. The last parameter is to return the total number of replacements. It is a reference variable, not what I want to specify how many times it will be replaced, so use str_replace( ) is not possible preg_replace() can be implemented, but it’s a pity that regular expressions are used,

The code is as follows	Copy code
$str=preg_replace('/abc/','xyz',$str,1); echo $str;

Is there any way to use regular expressions? Yes, it can be like this

The code is as follows  代码如下 复制代码 $replace='xyz'; if(($position=strpos($str,$replace))!==false){      $leng=strlen($replace);     $str=substr_replace($str,'xyz',$position,$leng); } echo $str;	Copy code

$replace='xyz';
if(($position=strpos($str,$replace))!==false){
$leng=strlen($replace);
$str=substr_replace($str,'xyz',$position,$leng);
}
echo $str;

http: //www.bkjia.com/PHPjc/632792.htmlWe will all use the str_replace function to replace strings in php. This function can also use regular expressions. The editor below Let me introduce to you how to replace some characters in a string or replace the first...