Java中的break语句，标签

Java的break语句用于在处理过程中终止循环。我们在Java程序中使用break保留关键字来跳出循环。

Java中的break

有两种形式的break语句 – 无标签和有标签。大多数情况下，break语句用于根据某些条件终止循环，例如当达到退出命令时中止处理。无标签的break语句用于终止包含它的循环，并可与switch、for、while和do-while循环一起使用。

在Java示例中打断

以下是一个示例，展示了在Java中如何使用break语句来中断for循环、while循环和do-while循环。

package com.Olivia.util;

package com.Olivia.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);
	}

}

Java 中的 break label可以被替换为以下的方式：

标记的break语句用于终止外循环，循环必须被标记才能起作用。下面是一个示例展示Java中的break标签语句的使用。

package com.Olivia.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 + "]");
	}

}