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3 methods: 1. Use substr_replace() to replace the first character with a null character, the syntax is "substr_replace($str,'',0,1)"; 2. Use substr() to replace the first character with a null character. Start intercepting all the remaining characters from 2 characters, the syntax is "substr($str,1)"; 3. Use mb_substr() to intercept all the remaining characters starting from the 2nd character, the syntax is "mb_substr($str,1, the remaining The number of characters, "character encoding")".
The operating environment of this tutorial: windows7 system, PHP8.1 version, DELL G3 computer
Remove the php string 3 methods for the first character
Method 1: Use the substr_replace() function to replace the first character of the string with an empty character
## The #substr_replace() function can replace the specified number of characters starting from the specified position in the string. If you want to replace the first character of the string with a null character, you only need to set the second parameter to the null character "''" and the third parameter to "0", the fourth parameter can be set to 1. (The index of characters in the string starts with 0, so the starting position of the first character is 0)
<?php header('content-type:text/html;charset=utf-8'); $str = 'hello world!'; echo "原字符串:".$str."<br><br>"; $replace = ''; echo "删除第一位字符:".substr_replace($str, $replace,0,1)."<br>"; ?>
Method 2: Use the substr function to intercept all remaining characters starting from the second character of the string
The substr() function can intercept characters of a certain length from the specified position of the string. You only need to set the second parameter of the function to 1 and omit the third parameter. Example:<?php header('content-type:text/html;charset=utf-8'); $str="Hello world"; echo "原字符串:".$str."<br>"; echo "删除第一位字符:".substr($str,1); ?>Note: The substr() function has no problem processing English, but in development we often deal with Chinese characters More generally, although the substr() function can also handle Chinese, it is not perfect.
<?php header('content-type:text/html;charset=utf-8'); $str="欢迎来到PHP中文网"; echo "原字符串:".$str."<br>"; echo "删除第一位字符:".substr($str,1); ?>At this time, you need to use the mb_substr() function.
Method 3: Use the mb_substr() function to intercept all the remaining characters starting from the second character of the string
The mb_substr() function can also be used to intercept the remaining characters from the string. Intercept characters of a certain length at the specified position; and the mb_substr() function is not only valid for English characters, but also for Chinese characters.<?php header('content-type:text/html;charset=utf-8'); $str="欢迎来到PHP中文网"; echo "原字符串:".$str."<br>"; echo "删除第一位字符:".mb_substr($str,1,mb_strlen($str)-3,"utf-8"); ?>
Description: Function used
1, substr_replace() function
substr_replace() function replaces part of a string with another string.substr_replace(string,replacement,start,length)
Description | |
---|---|
string | Required. Specifies the string to check.|
replacement | Required. Specifies the string to be inserted.|
start | Required. Specifies where in the string to begin replacement.
|
length | Optional. Specifies how many characters to replace. The default is the same as the string length.
|
参数 | 描述 |
---|---|
string | 必需。规定要返回其中一部分的字符串。 |
start | 必需。规定在字符串的何处开始。
|
length | 可选。规定要返回的字符串长度。默认是直到字符串的结尾。
|
返回值:返回字符串的提取部分,如果失败则返回 FALSE,或者返回一个空字符串。
3、mb_substr()函数
mb_substr() 函数可以从一个字符串中截取指定的一部分,与 substr() 函数不同的是,mb_substr() 函数不仅对英文字符有效,对中文字符同样有效。
mb_substr(string,start,length,encoding)
参数 | 描述 |
---|---|
str | 必需。从该 string 中提取子字符串。 |
start | 必需。规定在字符串的何处开始。
|
length | 可选。规定要返回的字符串长度。默认是直到字符串的结尾。
|
encoding | 可选。字符编码。如果省略,则使用内部字符编码。 |
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