How do I break out of nested loops in Java?

Question

I\'ve got a nested loop construct like this:

for (Type type : types) {
    for (Type t : types2) {
         if (some condition) {
             // Do somethin         


        

Answer 1

Labeled break concept is used to break out nested loops in java, by using labeled break you can break nesting of loops at any position. Example 1:

loop1:
 for(int i= 0; i<6; i++){
    for(int j=0; j<5; j++){
          if(i==3)
            break loop1;
        }
    }

suppose there are 3 loops and you want to terminate the loop3: Example 2:

loop3: 
for(int i= 0; i<6; i++){
loop2:
  for(int k= 0; k<6; k++){
loop1:
    for(int j=0; j<5; j++){
          if(i==3)
            break loop3;
        }
    }
}

Answer 2

Use Labels.

INNER:for(int j = 0; j < numbers.length; j++) {
    System.out.println("Even number: " + i + ", break  from INNER label");
    break INNER;
}

Refer to this article

Answer 3

Java 8 Stream solution:

List<Type> types1 = ...
List<Type> types2 = ...

types1.stream()
      .flatMap(type1 -> types2.stream().map(type2 -> new Type[]{type1, type2}))
      .filter(types -> /**some condition**/)
      .findFirst()
      .ifPresent(types -> /**do something**/);

Answer 4

Java does not have a goto feature like there is in C++. But still, goto is a reserved keyword in Java. They might implement it in the future. For your question, the answer is that there is something called label in Java to which you can apply a continue and break statement. Find the code below:

public static void main(String ...args) {
    outerLoop: for(int i=0;i<10;i++) {
    for(int j=10;j>0;j--) {
        System.out.println(i+" "+j);
        if(i==j) {
            System.out.println("Condition Fulfilled");
            break outerLoop;
        }
    }
    }
    System.out.println("Got out of the outer loop");
}

Answer 5

Like @1800 INFORMATION suggestion, use the condition that breaks the inner loop as a condition on the outer loop:

boolean hasAccess = false;
for (int i = 0; i < x && hasAccess == false; i++){
    for (int j = 0; j < y; j++){
        if (condition == true){
            hasAccess = true;
            break;
        }
    }
}

Answer 6

It's fairly easy to use label, You can break the outer loop from inner loop using the label, Consider the example below,

public class Breaking{
    public static void main(String[] args) {
        outerscope:
        for (int i=0; i < 5; i++) {
            for (int j=0; j < 5; j++) {
                if (condition) {
                    break outerscope;
                }
            }
        }
    }
}

Another approach is to use the breaking variable/flag to keep track of required break. consider the following example.

public class Breaking{ 
    public static void main(String[] args) {
        boolean isBreaking = false;
        for (int i=0; i < 5; i++) {
            for (int j=0; j < 5; j++) {
                if (condition) {
                    isBreaking = true;
                    break;
                }
            }
            if(isBreaking){
                break;
            }
        }
    }
}

However, I prefer using the first approach.