difference between libraries and helpers in php frameworks

Question

if i've got string functions i use a lot, should i put them in a helper class or a library class?

functions like: truncate string if longer than 30 characters, return a random string, make all lower cases and so on. these are functions that i probably don't need to create an object for. it's better to use them as static methods.

should i put them in a library class or a helper class?

when do i know when to put where?

Answer 1

Helpers are the classes that help something already there for example there can be a helper for:

array
string
url
etc

A library is something that can be any solution; it could be created for the first time by you and no one else has created.

Because you are dealing with a string (something already there), you should put it in a helper class, or modify the string helper class of the framework (if there is one). However, this is a convention or standard but you can create a library for it too if you are creating something really cool for string handling with quite some functions.