System.out.print("Enter first integer: "); //prompt
System is a class. Class System is part of package java.lang. Notice that class System is not imported with an import declaration at the beginning of the program.
**By default, package java.lang is imported in every Java program; thus, classes in java.lang are the only ones in the java API that do not require an import declaration.
excerpted from "Java how to program,by Deitel"
Example of usage of a class from an imported package:
ReplyDeleteimport java.util.Scanner;
Scanner input = new Scanner (System.in);
number1 = input.nextInt();