essay6.txt

Java Essay Serials 1 - Java Basics - 6, How a Java program jump out a nested loop?
Within a loop statement, such as for,while and do-while statement, a break statement will terminate the loop execution and jump to the next statement following the loop.
for exmaple:
    int m=0;
    while(m<5){  
        if(m==2){  
            break;  
        }  
        System.out.println(m);
        m++;  
    }  
    System.out.println("terminate while statement.");  
the above code snippet will output:
0
1
terminate while statement.

with nested loop statements, the break statement only jump out the inner loop.
for example:
		for (int n=0;n<3;n++) {
		    int m=0;
		    while(m<5){  
		        if(m==2) break; 
		        System.out.println(n+"-"+m);
		        m++;
		    }  
		    System.out.println("terminate while statement.");  
		}
the above code snippet will output the following:
0-0
0-1
terminate while statement.
1-0
1-1
terminate while statement.
2-0
2-1
terminate while statement.
It apparently shows that the break statement only jump out the inner while loop.

To jump out a nested loop, you can use break with a label, for example:
		Label1:
		for (int n=0;n<3;n++) {
		    int m=0;
		    while(m<5){  
		        if(m==2) break Label1;  
		        System.out.println(n+"-"+m);
		        m++;
		    }  
		    System.out.println("terminate while statement.");  
		}
		
		System.out.println("terminate for loop.");
The running result will be:
0-0
0-1
terminate for loop.