Example of Switch

SwitchExample.c

/*Example from book the C programing language
* by Brian W.Kernighan and Dennis M. Ritchie
*/
#include <stdio.h>
int main(){
    int c, i, nwhite, nother, ndigit[10];
    
    nwhite = nother = 0;
    //reset the array to 0
    for (i = 0; i < 10; i++)
        ndigit[i] = 0;
    while ((c = getchar()) != EOF){
        switch(c){
            case '0': case '1':case '2': case '3':case '4':
            case '5': case '6':case '7': case '8':case '9':
                //ndigit[c]++;
                //you may ask why don't we use it
                //the reason is c store an int code match with char not 
                //an actual int, in this case '0' is 48, it's out of range of 
                //our ndigit array
                ndigit[c-'0']++;
                break;
            case ' ':
            case '\n':
            case '\t':
                nwhite++;
                break;
            default:
                nother++;
                break;
        }
    }
    printf("digits = ");
    for (i = 0; i < 10; i++)
        printf(" %d", ndigit[i]);
    printf(", white space = %d, other = %d\n", 
        nwhite, nother);
    return 0;
}