PHP usage of addslashes () and stripslashes () for backslash handling functions

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PHP's own library functions Addslashes () and Stripslashes () are string-processing class functions that are the opposite:

Addslashes (): Adds a backslash to some of the predefined characters in the input string, which is required for database query statements, and so on. These predefined characters are: Single quotation mark ('), double quotation mark ("), backslash (\), NULL.

Stripslashes (): Removes the backslash added by the addslashes () function. This function cleans up data retrieved from a database or HTML form. (if two consecutive backslashes, remove one, keep one; if there is only one backslash, remove it directly.) )

PS: By default, PHP instruction MAGIC_QUOTES_GPC is on, and automatically runs Addslashes () for all GET, POST, and COOKIE data. Do not use Addslashes () for strings that have been MAGIC_QUOTES_GPC escaped, because this results in double-layer escaping. You can use the function GET_MAGIC_QUOTES_GPC () to detect this situation. Cases:

if (GET_MAGIC_QUOTES_GPC ()) {
Code ....
}

Addslashes () Example:

<?php
$str = "Who ' s John Adams?";
Echo $str. "This isn't safe in a database query.<br/>";
echo addslashes ($STR). "This is safe in a database query.";
?>

Output:

Who ' s John Adams? This is the not safe in a database query.
Who\ ' s John Adams? This is safe in a database query.

Stripslashes () Example:

<?php
Echo stripslashes ("who\ ' s John Adams?");
?>

Output:

Who ' s John Adams?

PHP usage of addslashes () and stripslashes () for backslash handling functions