"break" Statements

Java Tutorials - Herong's Tutorial Examples

∟"break" Statements

This section describes 'break' statement, which is a branching statement that transfers the control to the end of the immediate enclosing 'switch', 'while', 'do', or 'for' statement.

"break" statements have 2 forms: non-labeled "break" statements and labeled "break" statements. Let's look at non-labeled "break" statements in this tutorial first.

What Is Non-Labeled "break" Statement? - A non-labeled "break" statement is a branching statement that transfers the control to the end of the immediate enclosing "switch", "while", "do", or "for" statement.

Here is the syntax for a non-labeled "break" statement.

switch|while|do|for ... {
   ...
   break
   ...
}
// break continues here

Note that non-labeled "break" statements can not be used in statements other than "switch", "while", "do", or "for" statements.

Here is a sample program that shows you how to use non-labeled "break" statements:

/* BreakStatementTest.java
 * Copyright (c) HerongYang.com. All Rights Reserved.
 */
class BreakStatementTest {
   public static void main(String[] arg) {
      java.io.PrintStream out = System.out;
      int max = 20;

      out.println("\"break\" statement in a single-level loop:");
      int sum = 0;
      int i = 1;
      while (true) { // loop level 1
         if (i > max ) break;
         sum += i;
         i++;
      } // break continues here
      out.println("   Sum of 1 to 20: "+sum);

      boolean isPrime;
      i = 3;
      out.println("\"break\" statement in a multi-level loop:");
      while (i < max) { // loop level 1
         isPrime = true;
         int j = 2;

         while (j < i) { // loop level 2
            isPrime = i%j > 0;
            if (!isPrime) break;
            j++;
         } // break continues here

         if (isPrime) out.println("   "+i+" is a prime number.");
         i++;
      }
   }
}

If you compile and run the above program, you will see:

herong> java BreakStatementTest.java

"break" statement in a single-level loop:
   Sum of 1 to 20: 210

"break" statement in a multi-level loop:
   3 is a prime number.
   5 is a prime number.
   7 is a prime number.
   11 is a prime number.
   13 is a prime number.
   17 is a prime number.
   19 is a prime number.