Break Nested Loops in Java

Mohammad Irfan Jan 25, 2023 Jun 07, 2021
  1. Break the Inner Loop Using a break Statement in Java
  2. Break a nested Loop Using a break Statement With a Label in Java
  3. Break a Nested Loop Using a break Statement in Java
  4. Break a nested Loop Using a flag Variable in Java
  5. Break a nested Loop Using a return Statement in Java
Break Nested Loops in Java

This tutorial introduces ways on how to break out nested loops in Java. We included some example programs you can follow as your guide.

A loop is a technique that allows us to repeat any code statement at any number of times depending on the given condition. Java supports several types of loops like the while loop, do-while loop, for loop, and for-each loop. We can nest these loops as well.

In this article, you’ll learn how to break out a nested loop in Java. There are several ways to break a nested loop; these include using break and return statements. Read on to find out more!

Break the Inner Loop Using a break Statement in Java

If you want to break out a loop, then you can use the break statement. This statement would break the inner loop only if you applied it in the inner loop. Here’s how you can do it:

public class SimpleTesting{
    public static void main(String[] args) {

        for (int i = 0; i < 5; i++) {
            for (int j = 0; j < 5; j++) {
                System.out.println(j);
                if(i==2) {
                    System.out.println("loop break");
                    break;
                }
            }
            System.out.println();
        }
    }
}

Output:

0
1
2
3
4

0
1
2
3
4

0
loop break

0
1
2
3
4

0
1
2
3
4

Break a nested Loop Using a break Statement With a Label in Java

If you want to break all the loops, both inner and outer, you can use a label with a break statement that will cut out all the loops and move control to the outside loop. See the example below:

public class SimpleTesting{
    public static void main(String[] args) {
        out:
        for (int i = 0; i < 5; i++) {
            for (int j = 0; j < 5; j++) {
                System.out.println(j);
                if(i==2) {
                    System.out.println("loop break");
                    break out;
                }
            }
            System.out.println();
        }
    }
}

Output:

0
1
2
3
4

0
1
2
3
4

0
loop break

Break a Nested Loop Using a break Statement in Java

A loop can of the while, for, or for-each types, and we can use a break statement in any of these loops. In this example, we are using a while loop and breaking its flow by using a break statement. See the example below:

public class SimpleTesting{
    public static void main(String[] args) {
        int i = 0;
        out:
            while (i<5) {
                int j = 0;
                while (j<5) {
                    System.out.println(j);
                    if(i==2) {
                        System.out.println("loop break");
                        break out;
                    }
                    j++;
                }
                System.out.println();
                i++;
            }
    }
}

Output:

0
1
2
3
4

0
1
2
3
4

0
loop break

Break a nested Loop Using a flag Variable in Java

This method introduces another scenario where we are using a variable in the loop condition; when the condition has been met, the loop breaks out. This code is good if you don’t want to use a break statement. This process is also better because it makes the code more readable. Follow the code block below:

public class SimpleTesting{
    public static void main(String[] args) {
        boolean flag = false;
        for (int i = 0; i < 5 && !flag; i++) {
            System.out.println(i);
            if(i==3) {
                System.out.println("loop break");
                flag = true;
            }
        }
    }
}

Output:

0
1
2
3
loop break

Break a nested Loop Using a return Statement in Java

The return statement in Java is used to convey a response back to the caller method. We can use a return statement in the loop to break it. It is an alternate of a break statement but it can only work in certain scenarios only. See the example below:

public class SimpleTesting{
    public static void main(String[] args) {
        boolean isStop = iterate();
        if(isStop)
            System.out.println("Loop stop");
        else System.out.println("Loop not stop");
    }
    static boolean iterate() {
        for (int i = 0; i < 5; i++) {
            for (int j = 0; j < 5; j++) {
                System.out.println(j);
                if(i==2) {
                    return true;
                }
            }
            System.out.println();
        }
        return false;
    }
}

Output:

0
1
2
3
4

0
1
2
3
4

0
Loop stop

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