inputting names on scanf

Question

I've been trying to make a small program for someone who is about to have their birthday and well, sadly I'm stuck in the first part, I insert

#include <stdio.h>
#include <stdlib.h>

int main(){
    char name[10];
    printf("Please enter your name. \n");
    scanf("%s", &name);
    if(name=='Mariana'){
        printf("Hello Onee-sama");
    }
    else if(name=='David'){
        printf("Im sure you're not my master");
    }
    else{
        printf("Sorry, you are not authorized");
    }
}

(I plead you ignore the abnormalities) and When i run it, whatever name I insert, it gives me the else response. I would really appreciate help :)

Your using single quotes for a const char[], use double quotes it will solve some of your problems. Also try using strcmp for string comparison — Andrei Tumbar, Dec 06 '16 at 01:16
@AndreiTumbar 1) A string literal is immutable, but not `const` qualified (that would be C++). 2) The single-quotes are still a valid expression: an `int`. This (and other errors) will show up with a modern compiler and warnings enabled. — too honest for this site, Dec 06 '16 at 01:31

score 1 · Answer 1 · edited May 23 '17 at 12:30

The code KopKoder wrote works perfect. Just adding explanation as to why strcmp or strncmp has to be used and not '==' operator. C strings are actually char arrays or pointer to char, which means that comparing a pointer to a const array will always give unexpected results. The link below gives better explanation to your question.

C String -- Using Equality Operator == for comparing two strings for equality

score 0 · Answer 2 · answered Dec 06 '16 at 01:31

0

You just need to use strcmp to compare C char arrays. Here is your code modified. Hope this helps!

#include <stdio.h>
#include <stdlib.h>

int main(){
    char name[10];
    printf("Please enter your name. \n");
    scanf("%s", &name);
    if( (strcmp(name,"Mariana")) == 0){
        printf("Hello Onee-sama");
    }
    else if((strcmp(name,"David"))==0){
        printf("Im sure you're not my master");
    }
    else{
       printf("Sorry, you are not authorized");
    }
}

answered Dec 06 '16 at 01:31

TheTotalJim

67
2
13

`scanf("%s", &name);` is as good as coding `gets()`. Neither make for a quality answer. `scanf("%9s", &name);` would be better . `fgets()` then handling the `'\n'` would even be better. – chux - Reinstate Monica Dec 06 '16 at 03:02

inputting names on scanf

2 Answers2