No, but it is not a bad idea to put default statements in switch statements for error- or logic-checking purposes. For instance, the following switch statement is perfectly normal:
1 2 3 4 5 6 7 8 | switch (char_code) {ase ‘Y’:case ‘y’: printf(“You answered YES!\n”);break;case ‘N’:case ‘n’: printf(“You answered NO!\n”);break;} |
Consider, however, what would happen if an unknown character code were passed to this switch statement. The program would not print anything. It would be a good idea, therefore, to insert a default case where this condition would be taken care of:
1 2 3 4 | ...default: printf(“Unknown response: %d\n”, char_code);break;... |
Additionally, default cases come in handy for logic checking. For instance, if your switch statement handled a fixed number of conditions and you considered any value outside those conditions to be a logic error, you could insert a default case which would flag that condition. Consider the following example:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 | void move_cursor(int direction) { switch (direction) { case UP: cursor_up(); break; case DOWN: cursor_down(); break; case LEFT: cursor_left(); break; case RIGHT: cursor_right(); break; default: printf(“Logic error on line number %ld!!!\n”,__LINE__); break; } } |
Dinesh Thakur holds an B.C.A, MCDBA, MCSD certifications. Dinesh authors the hugely popular