Java break语句，标签

冷不防 2023-02-28 08:43 20阅读 0赞

Java break statement is used to terminate the loop in between it’s processing. We use `break` reserve keyword for breaking out of the loop in java program.

Java break语句用于终止其处理之间的循环。 我们使用`break` reserve关键字来打破java程序中的循环。

## Java休息 **(****Java break****)** ##

There are two forms of break statement – **unlabeled** and **labeled**. Mostly break statement is used to terminate a loop based on some condition, for example break the processing if exit command is reached.

break语句有两种形式- **未标记**和**标记** 。 通常，break语句用于根据某些条件终止循环，例如，如果到达exit命令，则中断处理。

Unlabeled break statement is used to terminate the loop containing it and can be used with switch, for, while and do-while loops.

无标签的break语句用于终止包含它的循环，并且可以与switch，for，while和do-while循环一起使用。

### 闯入java示例 **(****break in java example****)** ###

Here is an example showing java break statement usage in for loop, while loop and do-while loop.

这是显示for循环，while循环和do-while循环中java break语句用法的示例。

package com.journaldev.util;
    
    package com.journaldev.util;
    
    public class JavaBreak {
    
    	public static void main(String[] args) {
    		String[] arr = { "A", "E", "I", "O", "U" };
    
    		// find O in the array using for loop
    		for (int len = 0; len < arr.length; len++) {
    			if (arr[len].equals("O")) {
    				System.out.println("Array contains 'O' at index: " + len);
    				// break the loop as we found what we are looking for
    				break;
    			}
    		}
    
    		// use of break in while loop
    		int len = 0;
    		while (len < arr.length) {
    			if (arr[len].equals("E")) {
    				System.out.println("Array contains 'E' at index: " + len);
    				// break the while loop as we found what we are looking for
    				break;
    			}
    			len++;
    		}
    
    		len = 0;
    		// use of break in do-while loop
    		do {
    			if (arr[len].equals("U")) {
    				System.out.println("Array contains 'U' at index: " + len);
    				// break the while loop as we found what we are looking for
    				break;
    			}
    			len++;
    		} while (len < arr.length);
    	}
    
    }

Note that if we remove break statement, there won’t be any difference in the output of the program. For small iterations like in this example, there is not much of a performance benefit. But if the [iterator][] size is huge, then it can save a lot of processing time.

请注意，如果我们删除break语句，程序的输出将不会有任何差异。 对于此示例中的小迭代，性能没有太大好处。 但是，如果[迭代器][iterator]大小很大，则可以节省大量处理时间。

### Java中断标签 **(****Java break label****)** ###

Labeled break statement is used to terminate the outer loop, the loop should be labeled for it to work.

标记为break的语句用于终止外部循环，应标记该循环才能使其正常工作。

Here is an example showing java break label statement usage.

这是显示java break标签语句用法的示例。

package com.journaldev.util;
    
    public class JavaBreakLabel {
    
    	public static void main(String[] args) {
    		int[][] arr = { { 1, 2 }, { 3, 4 }, { 9, 10 }, { 11, 12 } };
    		boolean found = false;
    		int row = 0;
    		int col = 0;
    		// find index of first int greater than 10
    		searchint:
    
    		for (row = 0; row < arr.length; row++) {
    			for (col = 0; col < arr[row].length; col++) {
    				if (arr[row][col] > 10) {
    					found = true;
    					// using break label to terminate outer statements
    					break searchint;
    				}
    			}
    		}
    		if (found)
    			System.out.println("First int greater than 10 is found at index: [" + row + "," + col + "]");
    	}
    
    }

We can also use break statement to get out of [switch-case statement][], you can learn about all these in below video.

我们还可以使用break语句摆脱[switch-case语句][switch-case statement] ，您可以在下面的视频中了解所有这些信息。

[演示地址][Link 1]

Reference: [Oracle Documentation][]

参考： [Oracle文档][Oracle Documentation]

> 翻译自: [https://www.journaldev.com/980/java-break-statement-label][https_www.journaldev.com_980_java-break-statement-label]

[iterator]: https://www.journaldev.com/13460/java-iterator
[switch-case statement]: https://www.journaldev.com/588/java-switch-case-string
[Link 1]: https://www.youtube.com/embed/K148NXHD-UM?feature=oembed
[Oracle Documentation]: https://docs.oracle.com/javase/tutorial/java/nutsandbolts/branch.html
[https_www.journaldev.com_980_java-break-statement-label]: https://www.journaldev.com/980/java-break-statement-label