How to remove the carriage return character in a string in php

4 methods: 1. Use ltrim() to remove the carriage return character on the left side of the string, the syntax is "ltrim(string)"; 2. Use rtrim() to remove the carriage return character on the right side of the string. , syntax "rtrim(string)"; 3. Use trim() to remove carriage returns on both sides of the string, syntax "trim(string)"; 4. Use preg_replace() with regular expressions to remove all carriage returns symbol, syntax "preg_replace('/\r|\n/','', string)".

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

php removes strings Methods for carriage returns

Method 1: Use ltrim() to remove

ltrim() can remove the carriage return on the left side of the string Character

<?php
header("Content-type:text/html;charset=utf-8");
$str="

676
sdfhg
ju80
87";
echo "去除回车符前：";
echo $str;
$str = ltrim($str); 
echo "\n去除回车符后：";
echo $str;
?>

Description: The

ltrim() function removes whitespace characters or other predefined characters on the left side of the string.

ltrim(string,charlist)

Parameters	Description
string	Required . Specifies the string to check.
charlist	Optional. Specifies which characters are removed from the string. If this parameter is omitted, all of the following characters are removed: "\0" - NULL "\t" - Tab "\n" - Newline "\x0B" - vertical tab "\r" - carriage return " " - space

Method 2: Use rtrim() to remove

rtrim() can remove the carriage return character on the right side of the string

<?php
header("Content-type:text/html;charset=utf-8");
$str="676
sdfhg
ju80
87

";
echo "去除回车符前：\n";
echo $str;
$str = rtrim($str); 
echo "去除回车符后：\n";
echo $str;

echo "结尾测试文本";
?>

Description:

rtrim() function removes blank characters or other predefined characters on the right side of the string.

rtrim(string,charlist)

Parameters can refer to ltrim().

Method 3: Use trim() to remove

trim() can remove carriage returns on both sides of the string

<?php
header("Content-type:text/html;charset=utf-8");
$str="

676
sdfhg
ju80
87

";
echo "去除回车符前：";
echo $str;
$str = trim($str); 
echo "去除回车符后：";
echo $str;

echo "结尾测试文本";
?>

Description:

trim() function removes blank characters or other predefined characters on both sides of a string.

trim(string,charlist)

Parameters can refer to ltrim().

Method 4: Use preg_replace() to remove

The preg_replace() function can be used with regular expressions to remove all carriage returns (line feeds).

The preg_replace function performs a regular expression search and replace.

Just use the preg_replace function to perform a regular expression search for carriage return characters in the string and replace them with empty characters.

Regular expression used: /\r|\n/

Example:

<?php
header("Content-type:text/html;charset=utf-8");
$str="

676
sdfhg
ju80
87

";
echo "去除回车符前：";
echo $str;
$str = preg_replace(&#39;/\r|\n/&#39;, &#39;&#39;, $str); 
echo "\n去除回车符后：";
echo $str;
?>

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