4 situations in which php removes spaces and special characters from text

In daily development, when processing some submitted content, it is often necessary to consider the blank content. Because if there are gaps in the submitted data, it will cause problems for the program. For example, when a user fills in their email address and accidentally adds spaces at the end or beginning, the email address submitted by the user will be incorrect. In order to avoid this situation, we It is necessary to remove the spaces from the data submitted by the user. In this chapter, I will introduce you to several methods on how to remove spaces?

: php complete self-study manual

The trim() function is provided in PHP to remove spaces and special characters on the left and right sides of a string.

trim(string,charlist)

Example

Remove spaces on both sides of the string:

<?php
header("content-type:text/html;charset=utf-8");
$str = "            Hello World!           ";
echo "不使用 trim: " . $str;
echo "<br>";
echo "使用 trim: " . trim($str);
?>

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Second type: remove the spaces on the left

ltrim() function removes the blank characters on the left side of the string or Other predefined characters. The syntax is as follows

ltrim(string,charlist)

实例

移除字符串左侧的空格：

<?php
header("content-type:text/html;charset=utf-8");
$str = "    PHP中文网";
echo "不使用 ltrim: " . $str;
echo "<br>";
echo "使用 ltrim: " . ltrim($str);
?>

运行结果查看源码结果如下图

第三种：去除右边的空格

rtrim() 函数移除字符串右侧的空白字符或其他预定义字符。语法如下

rtrim(string,charlist)

rtrim()函数的参数string是规定要检查的字符串，charlist参数是指定需要从字符串中去除那些特殊字符，与trim()和ltrim()函数一样，charlist参数的可选值如下表：

实例

移除字符串右侧的空格：

<?php
header("content-type:text/html;charset=utf-8");
$str = "PHP中文网    ";
echo "不使用 rtrim：" . $str;
echo "<br>";
echo "使用 rtrim：" . rtrim($str);
?>

运行结果查看源码结果如下图

第四种：去除所有的空格或特殊字符

str_replace() 函数以其他字符替换字符串中的一些字符（区分大小写）。str_replace() 函数是已替换的方式将字符串中的空格或特殊字符替换掉自己想要的，语法如下：

str_replace(find,replace,string,count)

参数详解：

find    必需。规定要查找的值。    
replace    必需。规定替换 find 中的值的值。    
string    必需。规定被搜索的字符串。    
count    可选。对替换数进行计数的变量。

实例

去除所有的空格

<?php
header("content-type:text/html;charset=utf-8");
$str = "      PHP     中     文   网    ";
echo $str."<br/>";
$re=str_replace(" ",&#39;&#39;,$str);
echo $re
?>

运行结果如下：

去除各种空格的几种方法已经给大家介绍了，希望对大家有所帮助.

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