Friday, 27 January 2017

TRANSFER STATEMENTS IN JAVA

1. break – We can use the break statements in the following cases.
  • ·        Within the switch to stop fall through.

Example –
public class Loop4 {
          public static void main(String[] args) {
                   int x=0;
                   switch(x)
                   {
                   case 0:
                             System.out.println(0);
                   case 1:
                             System.out.println(1);
                   case 2:
                             System.out.println(2);
                             break;
                   case 3:
                             System.out.println(3);
                   default:
                             System.out.println("default");
                   }
          }
}

Output –
0
1
2

  • ·        Inside the loop to break loop execution based on some condition.

Example –
public class Loop5 {
          public static void main(String[] args) {
                   for(int i=0;i<10;i++)
                   {
                             if(i==6)
                                      break;
                             System.out.print(i+" ");
                   }
          }
}

Output –
0 1 2 3 4 5

  • ·        Inside label blocks to break block execution based on some condition.

Example –
public class Loop6 {
          public static void main(String[] args) {
                   int x=10;
                   e1:{
                             System.out.println("begin");
                             if(x==10)
                                      break e1;
                             System.out.println("end");
                   }
                   System.out.println("hello");
          }
}

Output –
begin
hello

Note – These are the only places where we can use the break statement. If we use anywhere else then we will get compile time error.

Example –
public class Loop7 {
          public static void main(String[] args) {
                   int x=10;
                   System.out.println("begin");
                   if(x==10)
                             break;
                   System.out.println("end");
                   System.out.println("hello");
          }
}


2. continue statement – Sometimes, it is required to skip a part of the body of loop under specific conditions. So, C supports continue statement to overcome this anomaly. The working structure of continue is similar to that of break statement but the difference is that it cannot terminate the loop. It causes the loop to be continued with next iteration after skipping statements in between. Continue statement simply skips statements and continues next iteration. It is the keyword of C and the task of this keyword is to transfer the control of program at the beginning of the loop. Using continue is always optional but it should be placed within the loop body only. In implementation where we know the maximum number of repetitions but some condition is there where we need to skip the statements from repetition condition is there where we need to skip the statements from repetition process then go for continue.

Example –
public class Loop8 {
          public static void main(String[] args) {
                   int i;
                   for(i=0;i<10;i++)
                   {
                             if(i==5 || i==6)
                             {
                                      continue;
                             }
                             System.out.println("i value is : "+i);
                   }
          }
}

Output –
 i value is : 0
i value is : 1
i value is : 2
i value is : 3
i value is : 4
i value is : 7
i value is : 8
i value is : 9

Explanation –
1. A variable i of type int is declared.
2. A for loop is started and is initialized as 1 and condition is if i less than 10.
3. On the first cycle 0 is less than 10, so the condition is satisfied. Upto 0,1,2,3,4 print in console.
4. When i value is 5 and 6. In the for loop there is an if statement that states that if i equals to 5 or 6 then come out of the loop and when i becomes 7 then again it starts printing in console.

No comments:

Post a Comment