Thread: caesar cypher

I'm trying to create a program that first takes in a number that determines the amount of letters the second input (sentence) will go up. This is what I have so far:

Code:

#include <stdio.h>
#include <string.h>


int main(void){

    int  i=0,a=1;
    char sent[100];
    while(true){
            scanf("%d",&a);
            if(a == 0){
                 break;
                 }
                 
            gets(sent);
            
            while(sent[i]){
            if(sent[i] != " "){
                  sent[i] += a;
                    }
                  }
            printf("%s",sent);
                       
            }

    getchar();
    return 0;
    }

I get an error at the line: if(sent[i] != " "){

How come?

Also, even with that working, how come this program doesn't end up working ?

Thank you .