package org.apache.commons.lang does not exist [Netbeans]

Question

Am new to programming with basic knowledge and I\'ve taken a liken to Java.
I wanted to write a code that calculates a number to the nth power without using loops. I\'ve bee

Answer 1

http://commons.apache.org/proper/commons-lang/ states the following:

Note that Lang 3.0 (and subsequent versions) use a different package (org.apache.commons.lang3) than the previous versions (org.apache.commons.lang), allowing it to be used at the same time as an earlier version.

So change the package accordingly, or heed Richard Tingle's advice and left click the error+light bulb icon in the gutter (were line numbers are shown) and choose "Add import for...".

import org.apache.commons.lang3.StringUtils;