- Create a new class named BreakContinue.
- Add a new method named breakExample. As the class uses the Scanner class, don’t forget to import java.util.Scanner at the top of BreakContinue.
public static void breakExample(){ Scanner in = new Scanner(System.in); while(true){ System.out.print("Enter a number: "); if(in.hasNextDouble()){ break; } String word = in.next(); System.err.println(word + " is not a number."); } double x = in.nextDouble(); System.out.println("You entered: " + x); }
- Add main and have it call breakExample.
public static void main(String[] args){ BreakContinue.breakExample(); }
- Compile and run the program.
$ javac BreakContinue.java $ java BreakContinue Enter a number: x x is not a number. Enter a number: 12 You entered: 12.0
The complete class should appear as follows.
import java.util.Scanner; public class BreakContinue { public static void main(String[] args){ BreakContinue.breakExample(); } public static void breakExample(){ Scanner in = new Scanner(System.in); while(true){ System.out.print("Enter a number: "); if(in.hasNextDouble()){ break; } String word = in.next(); System.err.println(word + " is not a number."); } double x = in.nextDouble(); System.out.println("You entered: " + x); } }
- Add a method named continueExample to the class.
public static void continueExample(){ Scanner in = new Scanner(System.in); int x = -1; int sum = 0; while(x != 0){ System.out.println("Enter a number: "); x = in.nextInt(); if (x <=0){ continue; } System.out.println("Adding " + x); sum += x; } System.out.println("Sum: " + sum); }
- Comment the call to breakExample in main and add a call to continueExample.
public static void main(String[] args){ // BreakContinue.breakExample(); BreakContinue.continueExample(); }
- Compile and run the program.
$ javac BreakContinue.java $ java BreakContinue Enter a number: 1 Adding 1 Enter a number: 2 Adding 2 Enter a number: 3 Adding 3 Enter a number: 0 Sum: 6
The complete class should appear as follows.
import java.util.Scanner; public class BreakContinue { public static void main(String[] args){ //BreakContinue.breakExample(); BreakContinue.continueExample(); } public static void breakExample(){ Scanner in = new Scanner(System.in); while(true){ System.out.print("Enter a number: "); if(in.hasNextDouble()){ break; } String word = in.next(); System.err.println(word + " is not a number."); } double x = in.nextDouble(); System.out.println("You entered: " + x); } public static void continueExample(){ Scanner in = new Scanner(System.in); int x = -1; int sum = 0; while(x != 0){ System.out.println("Enter a number: "); x = in.nextInt(); if (x <=0){ continue; } System.out.println("Adding " + x); sum += x; } System.out.println("Sum: " + sum); } }
LearningLad provides tutorials on both the break and continue statements.