[JavaSE column 16] Java loop exit statement break, continue

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The break and continue statements are one of the loop exit statements in Java . This article will explain the break and continue statements in Java.

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1. The syntax of the break statement

In Java, the break statement is used to terminate the execution of a loop or switch statement and jump out of the current code block.

When a certain condition is met, you can use the break statement to end the loop early without waiting for the natural termination of the loop condition.

A code example of the break statement is as follows.

for (int i = 0; i < 10; i++) {
    
    
    if (i == 5) {
    
    
        break; // 当i等于5时，终止循环
    }
    System.out.println(i);
}

The above code uses a for loop to iterate, when the variable $i$ is equal to$At\; 5$ o'clock, executethe breakstatement, terminate the loop and jump out. Therefore, the code will output something like this:

0
1
2
3
4

notice when $i$ is equal to$5$ , the loop is terminated early and subsequent iterations are not executed.

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Second, the syntax of the continue statement

In Java, the continue statement is used to skip the remaining code of the current loop and start the next loop .

It will ignore all codes after the continue statement in the loop body, and directly enter the next loop , and its syntax is as follows:

continue;

Here is a concrete code example:

for (int i = 0; i < 5; i++) {
    
    
    if (i == 2) {
    
    
        continue; // 当i等于2时，跳过当前循环
    }
    System.out.println(i);
}

The above code uses a for loop to iterate, when the variable $i$ is equal to$At\; 2$ o'clock, executethe continue statement, skip the remaining code of the current loop, and proceed directly to the next round of loop. Therefore, the code will output something like this:

0
1
3
4

notice when $i$ is equal to$2$ , the corresponding value is skipped and not printed. The cycle then continues until$i$ is less than$5$ so far.

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3. Differences and usage scenarios of break and continue

In Java, both break and continue are keywords used to control the flow of loop execution , but their functions and usage scenarios are different.

3.1 break statement

• Function : Terminate the execution of the current loop or switch statement, and jump out of the current code block.
• Usage scenario : When a certain condition is met, it is necessary to end the loop early or jump out of the switch statement. You can use break to achieve this goal.

Common usage scenarios include:

1. In the loop, judge whether to terminate the loop according to certain conditions;
2. After executing a specific branch in the switch statement, the execution of the switch statement ends prematurely.

3.2 continue statement

• Function : Skip the remaining code of the current loop and start the next loop.
• Usage scenario : When a certain condition is met, it is necessary to skip part of the code of the current loop and directly enter the next loop, which can be achieved by using continue.

Common usage scenarios include:

1. In the loop, judge whether to skip the current iteration according to certain conditions;

2. In some cases it is desirable to skip specific loop iterations instead of terminating the entire loop.

3.3 Summary of usage scenarios

The break statement is used to terminate the execution of a loop or switch statement, and is suitable for scenarios where the loop needs to be terminated early or the switch statement needs to be jumped out of.

The continue statement is used to skip the remaining code of the current loop and enter the next loop, which is suitable for scenarios where specific iterations or conditions need to be skipped.

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Four. Summary

This article briefly introduces the loop exit statements break and continue in Java, explains the syntax, and demonstrates sample codes. In the next blog, I will explain the concepts and usage scenarios of stack and heap in Java.