Need to Import java.lang Package in Java Programs

The java.lang package is the default package in Java, by default, it will be imported. Therefore, there is no need to import this package explicitly. i.e. without importing you can access the classes of this package.

Example

If you observe the following example here we haven't imported the lang package explicitly but, still, we are able to calculate the square root of a number using the sqrt() method of the java.lang.Math class.

Live Demo

public class LangTest {
   public static void main(String args[]) {
      int num = 100;
      double result = Math.sqrt(num);
      System.out.println("Square root of the number: "+result);
   }
}

Output

Square root of the number: 10.0