break a for loop inside a switch statement

Question

I have a functionality where user will be prompted to choose one of the three options.

1. for insert
2. for delete
0. for quit

I have a infinite for loop which will continuously ask user to do something. If user choose 0, I want the infinite loop to break. I cannot figure out how to break a for loop inside switch case.

for(;;){
        printf("please enter :\n");
        printf("1 for INSERT\n");
        printf("2 for DELETE\n");
        printf("0 for quit\n");
        
        printf("what's your value ?\n");
        scanf("%d",&operation);
        switch(operation){
            case 1:
                 printf("you choose to INSERT. Please inter a value to insert\n");
                 scanf("%d",&value);
                 insertAtBeginning(value);
                 break;
            case 2:
                 printf("you choose to DELETE\n");
                 
                 deleteFromBeginning();
                 break;
            case 0:
                  break;
        }
}

For just three options, may as well use and `if/else if/else` chain; the switch gains you nothing, and blocks `break` from working. Of course, `goto` to a label just below the `for` loop is an option here as well. — ShadowRanger, Mar 06 '16 at 03:44

score 2 · Answer 1 · answered Mar 06 '16 at 03:46

Instead of an infinite for loop, you can use a while loop and check the value of operation instead and leave out the 0 case:

operation = -1;              // initialize
while (operation != 0) {     // check operation instead
    printf("please enter :\n");
    printf(" 1 for INSERT\n");
    printf("2 for DELETE\n");
    printf("0 for quit\n");

    printf("what's your value ?\n");
    scanf("%d",&operation);
    switch(operation){
        case 1:
             printf("you choose to INSERT. Please inter a value to insert\n");
             scanf("%d",&value);
             insertAtBeginning(value);
             break;
        case 2:
             printf("you choose to DELETE\n");

             deleteFromBeginning();
             break;
    }
}

score 1 · Answer 2 · answered Mar 06 '16 at 03:42

1

maybe u can try while(selection != 0) instead of infinite for loop

answered Mar 06 '16 at 03:42

Jones Joseph

4,703
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score 1 · Answer 3 · edited Mar 06 '16 at 05:02

1

Use a flag to decide when to break.

bool end = false;

for(;!end;) {
    switch(operation) {
        case 0:
            end = true;
            break;
    }
}

edited Mar 06 '16 at 05:02

Alex P

5,942
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answered Mar 06 '16 at 03:47

CrimsonKnights

77
2
9

score 0 · Answer 4 · answered Mar 06 '16 at 03:51

0

You can achieve it by putting a if condition for you condition 0 and put break. if (your-condition==0) break; The meaning behind break in switch statement doesn't mean exit from for loop, it just exit from switch case.

answered Mar 06 '16 at 03:51

Nithila Shanmugananthan

318
5
18

break a for loop inside a switch statement

4 Answers4