How to escape and anti-escape characters in php

In PHP, you can use the addslashes() function to escape characters, the syntax is "addslashes($str)"; you can use the stripslashes() function to reverse escape characters and restore an escaped character. A defined string with the syntax "stripslashes($str)".

The operating environment of this tutorial: windows7 system, PHP7.1 version, DELL G3 computer

In PHP, you can use the addslashes() function and stripslashes() function to realize character escaping and anti-escaping.

1. addslashes() function

addslashes() function is to add \ to the string and convert the specified string. Definition, the syntax format is as follows:

addslashes($str)

Among them, $str is the string to be escaped.

In the string returned by the addslashes() function, for the purpose of database queries and other statements, backslashes are added before certain characters. These characters are single quotes ', Double quotes ", backslashes \ and NULL.

Example:

<?php 
header("Content-type:text/html;charset=utf-8");
$sql = "select * from php where website=&#39;PHP中文网&#39;";
$str = addslashes($sql);
echo($str); 
?>

2. Stripslashes() function

stripslashes() function is to restore an escaped string, that is, to remove the backslash added to the string. The syntax format is as follows:

stripslashes($str)

Among them, $str is the string that needs to be restored.

stripslashes() function will return a character after removing the escaped backslash String (\' is converted to ', double backslash \\ is converted to single backslash \).

Example:

<?php 
header("Content-type:text/html;charset=utf-8");
$sql = "select * from php where website=\&#39;PHP中文网\&#39;";
$str = stripslashes($sql);
echo($str); 
?>

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