break 关键字

break用于终止循环，有两种形式的break语句： unlabeled 和 labeled。

 

unlabeled 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。

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);
    }
 
}

labeled的break语句用于终止外部循环，该循环应该标记为它工作。

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 +
                    "]");
    }
 
}