break语句在Java中做什么？ [英] What does break statement do in java?

问题描述

有人知道 group_skip 做什么吗？

也许这是一个基本的编程，但是我已经一直使用Java编程已有好几年，直到今天才发现。

Maybe it is a basic programming, but I've been programming using Java for some years and just found it today.

group_skip: do {
    event = stepToNextEvent(FormController.STEP_OVER_GROUP);
    switch (event) {
        case FormEntryController.EVENT_QUESTION:
        case FormEntryController.EVENT_END_OF_FORM:
            break group_skip;
    }
} while (event != FormEntryController.EVENT_END_OF_FORM);

谢谢！

推荐答案

这是标记循环， break group_skip; 语句被执行，它将跳出do while循环，该循环被标记为 group_skip

This is a labelled loop, when break group_skip; statement is executed, it will jump out of the do while loop which is labelled as group_skip

boolean isTrue = true;
    outer: for (int i = 0; i < 5; i++) {
        while (isTrue) {
            System.out.println("Hello");
            break outer;
        } // end of inner while
        System.out.println("Outer loop"); // does not print
    } // end of outer loop
   System.out.println("Good Bye");

此输出

Hello
Good Bye

您可以在这里弄清楚概念。

You can get the concept clear here.

• 有一个标记为的循环，称为外并且有内部而循环


• 在执行内部for循环时，遇到 break external; 语句


• 外部for循环的系统为。 out.println外部循环 语句，但不会打印出来。


• 这是因为中断外部导致控件直接跳出标记为的循环

• There is a labelled for loop called outer and there is inner while loop
• When inner for loop is being executed, it encounters break outer; statement
• The outer for loop has a System.out.println"Outer loop" statement but that does not get printed.
• This is because break outer causes the control to jump out of labelled for loop directly

现在 continue 语句

outer: for (int i = 0; i < 5; i++) {
        for (int j = 0; j < 5; j++) {
            System.out.println("Hello");
            continue outer;
        } // end of inner loop
        System.out.println("outer"); // this won't print
    } // end of outer loop
    System.out.println("Good bye");

此打印文件

Hello
Hello
Hello
Hello
Hello
Good bye

• 这里有一个标记为的循环和一个内部的循环


• 用于的内部循环打印你好并继续到外部循环。


• 因此，内部下面的语句用于循环被跳过，外部循环继续执行。


• 在外部 for loop，再见已打印


• There is a labelled for loop here and an inner for loop
• Inner for loop prints Hello and continues to the outer loop.
• Because of this, the statements below inner for loop are skipped and outer loop continues to execute.
• At the end of outer for loop, Good Bye is printed

希望这可以使所有内容清除。

Hope this makes everything clear.

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