Break_KetWord

Love The Way You Lie 2021-11-05 06:38 202阅读 0赞

## break Keyword in Java with Examples ##

The break keyword is used to prematurely exit a for, while, or do while loop or to mark the end of a case block in a switch statement.  
Let’s discuss how to use break keyword in for loop, while loop and switch statement with examples.

### 1. Using a break keyword to Exit a for Loop ###

By using a break, you can force immediate termination of a loop, bypassing the conditional expression and any remaining code in the body of the loop. When a break statement is encountered inside a loop, the loop is terminated and program control resumes at the next statement following the loop.  
Here is a simple example:

package net.javaguides.corejava.controlstatements.loops;
    
    public class BreakWithForLoop {
        public static void main(String args[]) {
            for (int i = 0; i < 100; i++) {
                if (i == 10)
                    break; // terminate loop if i is 10
                System.out.println("i: " + i);
            }
            System.out.println("Loop complete.");
        }
    }

Output:

i: 0
    i: 1
    i: 2
    i: 3
    i: 4
    i: 5
    i: 6
    i: 7
    i: 8
    i: 9
    Loop complete.```

As we can see, although the for loop is designed to run from 0 to 99, the break statement causes it to terminate early, when i equals 10.

### 2. Using break to Exit a while Loop ###

package net.javaguides.corejava.controlstatements.loops;
    
    public class BreakWithWhileLoop {
        public static void main(String args[]) {
            int i = 0;
            while (i < 100) {
                if (i == 10)
                    break; // terminate loop if i is 10
                System.out.println("i: " + i);
                i++;
            }
            System.out.println("Loop complete.");
        }
    }

Output

i: 0
    i: 1
    i: 2
    i: 3
    i: 4
    i: 5
    i: 6
    i: 7
    i: 8
    i: 9
    Loop complete.

### 3. Using break with Nested Loops ###

When break keyword used inside a set of nested loops, the break statement will only break out of the innermost loop.  
For example:

package net.javaguides.corejava.controlstatements.loops;
    
    public class BreakWithNestedLoops {
        public static void main(String args[]) {
            for (int i = 0; i < 3; i++) {
                System.out.print("Pass " + i + ": ");
                for (int j = 0; j < 100; j++) {
                    if (j == 10)
                        break; // terminate loop if j is 10
                    System.out.print(j + " ");
                }
                System.out.println();
            }
            System.out.println("Loops complete.");
        }
    }

Output:

Pass 0: 0 1 2 3 4 5 6 7 8 9 
    Pass 1: 0 1 2 3 4 5 6 7 8 9 
    Pass 2: 0 1 2 3 4 5 6 7 8 9 
    Loops complete.```

public class BreakSwitchCaseExample {
    
        public static void main(String args[]) {
            int num = 2;
    
            switch (num) {
                case 1:
                    System.out.println("Case 1 ");
                    break;
                case 2:
                    System.out.println("Case 2 ");
                    break;
                case 3:
                    System.out.println("Case 3 ");
                    break;
                default:
                    System.out.println("Default ");
            }
        }
    }

Output:

Case 2

Break_KetWord

发表评论取消回复

还没有评论，来说两句吧...

相关阅读