How to reverse a string using strrev() function in PHP? (code example)

Reversing a string is one of the most basic string operations. In PHP, you can use the built-in function strrev() to reverse a string. The following article will show you how to use the PHP strrev() function. I hope it will be helpful to you. [Video tutorial recommendation: PHP tutorial]

##PHP strrev() function# The ##strrev() function is a built-in function in PHP that can be used to reverse a string. This function does not make any changes to the original string passed to it as an argument.

Basic syntax:

string strrev($inpString)

Parameters:

strrev() function accepts a single parameter $inpString. This parameter is a string (English, Chinese, numeric, mixed string), which specifies the string we need to reverse. If you pass it a number, it treats it as a string of numbers and reverses it.

Return value:

The strrev() function returns the reversed string (English, Chinese, numbers, mixed strings). It does not make any changes to the original string passed in the parameter.

Examples of using the PHP strrev() function
Let’s take a look at how to use the PHP strrev() function through code examples. .

Example 1:

Use strrev() function to reverse English string

<?php  
$str = "hello!"; 
  
// 输出反转的字符串
echo strrev($str); 
?>

Output:

!olleh

Example 2:

Use the strrev() function to reverse numbers

<?php  
$num = 134; 
echo "反转前："; 
var_dump($num);
  
// 输出反转的数字
echo "反转后："; 
var_dump(strrev($num));
?>

Output:

反转前：int(134)
反转后：string(3) "431"

Description: The strrev() function will convert the number into a numeric string and then reverse it.

Example 3:

Use strrev() function to reverse Chinese

<?php  
header("content-type:text/html;charset=utf-8"); 
$str = "欢迎来到这里！"; 
function cnstrrev($str)
{
  $len = strlen($str);
  for($i = 0; $i < $len; $i++)
  {
    $char = $str{0};
    if(ord($char) > 127) //ord()函数取得第一个字符的ASCII码，如果大于0xa0(127)的话则是中文字符
    {
      $i+=2;//utf-8编码的情况下，一个中文字符占三个字节
      if($i < $len)
      {
        $arr[] = substr($str, 0, 3);//utf-8编码的情况下，一个中文字符占三个字节
        $str = substr($str, 3);
      }
    }
    else
    {
      $arr[] = $char;
      $str = substr($str, 1);//否则为非中文，占一个字符
    }
  }
  return join(array_reverse($arr));//以相反的元素顺序返回数组：
}
// 输出反转的字符串
echo &#39;反转前：&#39;.$str.&#39;<br><br>反转后：&#39;.cnstrrev($str);
?>

Output:

反转前：欢迎来到这里！

反转后：！里这到来迎欢

Instructions: Use strrev() function When reversing Chinese, the Chinese garbled problem will occur; we can solve the garbled problem by customizing a function in which it traverses the Chinese string and sets the encoding format.

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