Why is else if producing different results compared to a switch?-CodePudding

I have a simple piece of code that detects keystrokes using ncurses.

As I understand, 1 keypress pushes 3 values into the buffer. Where the 3rd value differentiates between arrow keys for example.

So when pressing any of the 4 arrows on the keyboard, the first 2 values pushed into the buffer should be similar \033, and [. But the 3rd value is unique to the arrow (A for up, B for down, C for right or D for left). Therefore, when mapping actions to keystrokes, we're depending on the 3rd value.

When trying to assess which arrow was pressed I tried both an if else ladder and a switch. The if else ladder works perfectly. But the switch seems to fire multiple cases on each keypress.

Here's the working code (if else) -

char first = getch(); //returns \033
char second = getch(); //returns [
char third = getch(); // returns A or B or C or D

if(third == 'A'){
printf("Up Arrow Pressed");
}
else if(third == 'B'){
printf("Down Arrow Pressed");
}
else if(third == 'C'){
printf("Right Arrow Pressed");
}
else if(third == 'D'){
printf("Left Arrow Pressed");
}

Here's the code that isn't working (Case) -

char first = getch(); //returns \033
char second = getch(); //returns [
char third = getch(); // returns A or B or C or D


switch(third){
    case('B'):
        printf("\nDOWN");
    case('C'):
        printf("\nRIGHT");
    case('A'):
        printf("\nUP");
    case('D'):
        printf("\nLEFT");
    default:
        printf("default");
    }

This is the output when cases are used and I press the down key:

CodePudding user response：

if you don't break; at the end of a case the next case is executed.

CodePudding user response：

If You Don't Use break at the end of each case then the cases that you write after the true case will also be executed.