In Java, the break and continue statements are used to control the flow of loops (for, while, do-while) and switch statements.
They provide ways to exit from a loop or skip certain iterations based on a condition.
In this tutorial, we’ll cover the usage of both break and continue statements with examples to demonstrate their behavior in different scenarios.
1. The break Statement
The break statement is used to exit a loop or a switch statement immediately. Once the break is encountered, the control jumps to the first statement outside the loop or switch block.
Syntax:
break;
Common Use Cases:
Exiting a loop early when a certain condition is met.
Exiting a switch case to avoid falling through to the next case.
Example 1: Using break in a for Loop
public class BreakInForLoop {
public static void main(String[] args) {
// For loop example
for (int i = 1; i <= 10; i++) {
if (i == 5) {
break; // Exit the loop when i is 5
}
System.out.println(i);
}
}
}
Explanation:
The for loop iterates from 1 to 10.
The break statement exits the loop when i == 5.
Output:
1 2 3 4
Example 2: Using break in a while Loop
public class BreakInWhileLoop {
public static void main(String[] args) {
int i = 1;
while (i <= 10) {
if (i == 6) {
break; // Exit the loop when i is 6
}
System.out.println(i);
i++;
}
}
}
Explanation:
The while loop continues until i reaches 10.
The break statement exits the loop when i == 6.
Output:
1 2 3 4 5
Example 3: Using break in a switch Statement
public class BreakInSwitchStatement {
public static void main(String[] args) {
int day = 3;
switch (day) {
case 1:
System.out.println("Monday");
break;
case 2:
System.out.println("Tuesday");
break;
case 3:
System.out.println("Wednesday");
break; // Exits the switch after this case
case 4:
System.out.println("Thursday");
break;
default:
System.out.println("Invalid day");
}
}
}
Explanation:
The switch statement checks the value of day.
When day == 3, it prints “Wednesday” and exits the switch block using break.
Output:
Wednesday.
2. The continue Statement
The continue statement is used to skip the current iteration of a loop and move to the next iteration. Unlike break, it does not exit the loop but skips the remaining code inside the loop for that specific iteration.
Syntax:
continue;
Common Use Cases:
Skipping certain iterations in a loop based on a condition.
Example 4: Using continue in a for Loop
public class ContinueInForLoop {
public static void main(String[] args) {
// For loop example
for (int i = 1; i <= 10; i++) {
if (i % 2 == 0) {
continue; // Skip the even numbers
}
System.out.println(i);
}
}
}
Explanation:
The for loop iterates from 1 to 10.
The continue statement skips the current iteration when i is even (i.e., i % 2 == 0).
Output:
1 3 5 7 9
Example 5: Using continue in a while Loop
public class ContinueInWhileLoop {
public static void main(String[] args) {
int i = 0;
while (i < 10) {
i++;
if (i % 3 == 0) {
continue; // Skip numbers divisible by 3
}
System.out.println(i);
}
}
}
Explanation:
The while loop continues as long as i < 10.
When i is divisible by 3, the continue statement skips the print statement and moves to the next iteration.
Output:
1 2 4 5 7 8 10
Example 6: Nested Loops with continue and break
In nested loops, break and continue affect only the innermost loop where they are used.
public class NestedLoops {
public static void main(String[] args) {
// Outer loop
for (int i = 1; i <= 3; i++) {
// Inner loop
for (int j = 1; j <= 3; j++) {
if (i == j) {
continue; // Skip when i == j
}
System.out.println("i = " + i + ", j = " + j);
}
}
}
}
Explanation:
The outer loop runs from 1 to 3.
The inner loop also runs from 1 to 3.
The continue statement skips printing when i == j.
Output:
i = 1, j = 2 i = 1, j = 3 i = 2, j = 1 i = 2, j = 3 i = 3, j = 1 i = 3, j = 2
3. Breaking and Continuing in Labeled Loops
Java allows the use of labeled loops, where a label is given to a loop, and you can break or continue that specific loop from within nested loops.
Syntax:
labelName:
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
if (condition) {
break labelName; // Exits the labeled loop
}
}
}
Example 7: Using break with Labeled Loops
public class BreakWithLabel {
public static void main(String[] args) {
// Labeled outer loop
outerLoop:
for (int i = 1; i <= 3; i++) {
for (int j = 1; j <= 3; j++) {
if (i == 2 && j == 2) {
break outerLoop; // Exit the outer loop when i == 2 and j == 2
}
System.out.println("i = " + i + ", j = " + j);
}
}
}
}
Explanation:
The break outerLoop exits both the inner and outer loops when i == 2 and j == 2.
Output:
i = 1, j = 1 i = 1, j = 2 i = 1, j = 3 i = 2, j = 1 Example 8: Using continue with Labeled Loops
public class ContinueWithLabel {
public static void main(String[] args) {
// Labeled outer loop
outerLoop:
for (int i = 1; i <= 3; i++) {
for (int j = 1; j <= 3; j++) {
if (i == 2 && j == 2) {
continue outerLoop; // Skip the inner loop and go to the next iteration of outer loop
}
System.out.println("i = " + i + ", j = " + j);
}
}
}
}
Explanation:
The continue outerLoop skips the remaining iterations of the inner loop when i == 2 and j == 2 and moves to the next iteration of the outer loop.
Output:
i = 1, j = 1 i = 1, j = 2 i = 1, j = 3 i = 2, j = 1 i = 3, j = 1 i = 3, j = 2 i = 3, j = 3
Conclusion
The break and continue statements provide powerful control over the flow of loops in Java:
break: Used to exit a loop or switch statement immediately.
continue: Used to skip the current iteration of a loop and continue with the next iteration.
Labeled loops allow you to specify which loop to break or continue when dealing with nested loops.
By understanding these control structures, you can write more flexible and efficient code.