如何在Android中启用使用String修改方法

Question

This may be a very simple question. I am new to Java programming. I couldn't find an answer in other threads.

When I try to use trim(), replace() or split() functions in Activity.java in Android Studio, they are not recognized. I understand I need to import some classes or enable some settings but don't know what to do.

element = element.trim();

trim is red and it says "Cannot resolve method trim" when I hover it.

Why?

Answer 1

element = element.toString().trim();