What is the use of import Java lang?

Can I import same package/class twice? … One can import the same package or same class multiple times . Neither compiler nor JVM complains about it. And the JVM will internally load the class only once no matter how many times you import the same class.

The import statement tells the compiler where to look for the external classes you use in your code . It needs to find them to check that you are using them correctly, calling methods that exist, passing the right arguments to them, etc. If you import java.io.

lang is auto-imported by every java program we write, hence all the classes in it are automatically available to us.

lang classes are always implicitly imported . This means that you do not have to import them manually (explicitly).