Java break Statement

Introduction

The break statement in Java is a control flow statement that is used to exit from a loop or a switch statement prematurely. It can be particularly useful for terminating loops early when a certain condition is met, or for exiting a switch case once a specific case has been executed. In this chapter, we will explore the syntax, usage, and examples of the break statement in Java.

Syntax

The basic syntax of the break statement is as follows:

break;

Key Points:

• The break statement can be used inside loops (for, while, do-while) and switch statements.
• When the break statement is executed, control immediately exits the loop or switch statement and proceeds to the next statement following the loop or switch.

Using break in Loops

Example: Exiting a for Loop

Let’s consider an example where we use the break statement to exit a for loop when a specific condition is met.

Example Code:

public class BreakForLoopExample {
    public static void main(String[] args) {
        // Loop from 1 to 10
        for (int i = 1; i <= 10; i++) {
            // Exit the loop if i equals 5
            if (i == 5) {
                break;
            }
            // Print the current value of i
            System.out.println("i: " + i);
        }
        // This statement is executed after the loop terminates
        System.out.println("Loop terminated.");
    }
}

Output:

i: 1
i: 2
i: 3
i: 4
Loop terminated.

Example: Exiting a while Loop

Let’s consider an example where we use the break statement to exit a while loop when a specific condition is met.

Example Code:

public class BreakWhileLoopExample {
    public static void main(String[] args) {
        int count = 1;
        // Loop while count is less than or equal to 10
        while (count <= 10) {
            // Exit the loop if count equals 5
            if (count == 5) {
                break;
            }
            // Print the current value of count
            System.out.println("Count: " + count);
            count++;
        }
        // This statement is executed after the loop terminates
        System.out.println("Loop terminated.");
    }
}

Output:

Count: 1
Count: 2
Count: 3
Count: 4
Loop terminated.

Example: Exiting a do-while Loop

Let’s consider an example where we use the break statement to exit a do-while loop when a specific condition is met.

Example Code:

public class BreakDoWhileLoopExample {
    public static void main(String[] args) {
        int count = 1;
        // Loop at least once, then while count is less than or equal to 10
        do {
            // Exit the loop if count equals 5
            if (count == 5) {
                break;
            }
            // Print the current value of count
            System.out.println("Count: " + count);
            count++;
        } while (count <= 10);
        // This statement is executed after the loop terminates
        System.out.println("Loop terminated.");
    }
}

Output:

Count: 1
Count: 2
Count: 3
Count: 4
Loop terminated.

Using break in switch Statement

Example: Exiting a switch Case

Let’s consider an example where we use the break statement to exit a switch case after executing the corresponding block of code.

Example Code:

public class BreakSwitchExample {
    public static void main(String[] args) {
        int day = 3;
        // Determine the day of the week
        switch (day) {
            case 1:
                System.out.println("Monday");
                break;
            case 2:
                System.out.println("Tuesday");
                break;
            case 3:
                System.out.println("Wednesday");
                break;
            case 4:
                System.out.println("Thursday");
                break;
            case 5:
                System.out.println("Friday");
                break;
            case 6:
                System.out.println("Saturday");
                break;
            case 7:
                System.out.println("Sunday");
                break;
            default:
                System.out.println("Invalid day");
                break;
        }
    }
}

Output:

Wednesday

Diagram: Flow Chart of break Statement in a Loop

   Start
     |
 [initialize]
     |
 [condition]
     |
    / \
   /   \
True  False
 /       \
[check    End
 break]
 / \
True False
 |     |
End   [execute]
       |
     [update]
       |
   [condition]

Conclusion

The break statement is a powerful control flow statement in Java that allows you to exit loops and switch cases prematurely. It enhances the flexibility of your code by providing a way to terminate execution based on specific conditions. Understanding how to use the break statement effectively can help you write more efficient and readable Java programs.