What does this PHP error mean? Call to undefined function addSlashesIfNeeded() -

What does this PHP error mean? Call to undefined function addSlashesIfNeeded() -

getting error:

fatal error: phone call undefined function addslashesifneeded() in ** on line 0

can tell me error means? , perchance solution?

thank you.

looks code calls custom function called addslashesifneeded() , code isn't including whatever reason. need find file function defined , include in page trying phone call it.

php