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How to find the first character of a string in php

青灯夜游
青灯夜游Original
2022-08-16 19:42:1010012browse

4 methods: 1. Use the "$string variable name[0]" statement; 2. Use substr() to intercept the first character, the syntax is "substr(English string,0,1)" ; 3. Use mb_substr() to intercept the first character, the syntax is "mb_substr(Chinese string, 0,1, encoding)"; 4. Use mb_strcut() to intercept the first character, the syntax is "mb_strcut(Chinese string, 0 ,3,encoding)" or "mb_strcut(English string,0,1,encoding)".

How to find the first character of a string in php

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

php gets the string Several methods for the first character in

Method 1: Use the $string variable name[0] statement to obtain the

Seen as a character collection (array), the first value of the array is the value of the element with index 0.

Note: Chinese strings are not applicable!

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);   
$str = &#39;hello&#39;;
echo "原字符串为:";
var_dump($str);
echo "字符串的第一个字符为:".$str[0];
?>

How to find the first character of a string in php

Method 2: Use the substr() function to intercept the first character

The substr() function can extract the first character from the string Intercept characters of a certain length at the specified position.

substr(string,start,length)
Parameters Description
string Required . Specifies a part of the string to be returned.
start Required. Specifies where in the string to begin.
  • Positive number - starts at the specified position in the string
  • Negative number - starts at the specified position from the end of the string
  • 0 - at the first character in the string Start at
length Optional. Specifies the length of the string to be returned. The default is until the end of the string.
  • Positive number - Returns from the position of the start parameter
  • Negative number - Returns from the end of the string

Just set the second parameter of the function to 0 and the third parameter to 1

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);   
$str = &#39;Ahello&#39;;
echo "原字符串为:";
var_dump($str);
echo "字符串的第一个字符为:".substr($str,0,1)."<br>";
?>

How to find the first character of a string in php

Note: Chinese strings are not applicable!

Method 3: Use the mb_substr() function to intercept the first character

The mb_substr() function can intercept a specified part of a string, similar to substr() The difference between the functions is that the mb_substr() function is not only valid for English characters, but also for Chinese characters.

mb_substr(string,start,length,encoding)
Parameters Description
str Required . Extracts a substring from this string.
start Required. Specifies where in the string to begin.
  • Positive number - starts at the specified position in the string
  • Negative number - starts at the specified position from the end of the string
  • 0 - at the first character in the string Start at
length Optional. Specifies the length of the string to be returned. The default is until the end of the string.
  • Positive number - Returns from the position of the start parameter
  • Negative number - Returns from the end of the string
encoding Optional. Character Encoding. If omitted, the internal character encoding is used.

You only need to set the second parameter of the function to 0 and the third parameter to 1

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);   
$str = &#39;Mhello&#39;;
echo "原字符串为:";
var_dump($str);
echo "字符串的第一个字符为:".mb_substr($str,0,1,"utf-8")."<br><br><br>";

$str = &#39;欢迎来到PHP中文网&#39;;
echo "原字符串为:";
var_dump($str);
echo "字符串的第一个字符为:".mb_substr($str,0,1,"utf-8")."<br>";
?>

How to find the first character of a string in php

Method 4: Use mb_strcut() to intercept the first character

mb_strcut() and mb_substr() are somewhat similar and can be set Character encoding, but the difference is that mb_substr splits characters by words, while mb_strcut splits characters by bytes but does not produce half a character. That is:

  • mb_substr() function represents a unit for either English or Chinese characters.

  • mb_strcut() function has 3 units for Chinese characters and 1 unit for English characters.

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);   
$str = &#39;Bhello&#39;;
echo "原字符串为:";
var_dump($str);
echo "字符串的第一个字符为:".mb_strcut($str,0,1,"utf-8")."<br><br><br>";

$str = &#39;欢迎来到这里&#39;;
echo "原字符串为:";
var_dump($str);
echo "字符串的第一个字符为:".mb_strcut($str,0,3,"utf-8")."<br>";
?>

How to find the first character of a string in php

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