To escape special characters in a PHP string, you can use the backslash \ followed by the character you want to insert. For example \$ for a dollar sign to prevent variable interpolation.

Other examples:

• \\ for a backslash
• \' for a single quote
• \" for a double quote
• \n for a new line
• \r for a carriage return
• \t for a tab

Escaping special characters from a posted value

To escape all special characters from a posted value, you can use this function:

$user_last_name = mysqli_real_escape_string($conn, $_POST['user_last_name']);