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 something and break...              break; // Breaks out of the inner loop          }     } } 

Now how can I break out of both loops? I've looked at similar questions, but none concerns Java specifically. I couldn't apply these solutions because most used gotos.

I don't want to put the inner loop in a different method.

I don't want to return the loops. When breaking I'm finished with the execution of the loop block.

Answer 1

Like other answerers, I'd definitely prefer to put the loops in a different method, at which point you can just return to stop iterating completely. This answer just shows how the requirements in the question can be met.

You can use break with a label for the outer loop. For example:

public class Test {     public static void main(String[] args) {         outerloop:         for (int i=0; i < 5; i++) {             for (int j=0; j < 5; j++) {                 if (i * j > 6) {                     System.out.println("Breaking");                     break outerloop;                 }                 System.out.println(i + " " + j);             }         }         System.out.println("Done");     } } 

This prints:

0 0 0 1 0 2 0 3 0 4 1 0 1 1 1 2 1 3 1 4 2 0 2 1 2 2 2 3 Breaking Done 

Answer 2

Technically the correct answer is to label the outer loop. In practice if you want to exit at any point inside an inner loop then you would be better off externalizing the code into a method (a static method if needs be) and then call it.

That would pay off for readability.

The code would become something like that:

private static String search(...)  {     for (Type type : types) {         for (Type t : types2) {             if (some condition) {                 // Do something and break...                 return search;             }         }     }     return null;  } 

Matching the example for the accepted answer:

 public class Test {     public static void main(String[] args) {         loop();         System.out.println("Done");     }      public static void loop() {         for (int i = 0; i < 5; i++) {             for (int j = 0; j < 5; j++) {                 if (i * j > 6) {                     System.out.println("Breaking");                     return;                 }                 System.out.println(i + " " + j);             }         }     } }