Thread: scanning variable without address of variable

I wrote this program that show result with scanning address of variable (scanf("%s", &name))

Code:

#include <stdio.h> 
int main()
{
    char name[100];
 
    printf("Enter a Name of candidate \n");
    scanf("%s", &name);
 
    printf("Name of candidate is  %s\n",name);
    
    return 0;
}

Enter a Name of candidate
Dev
Name of candidate is Dev

again I wrote program without & (scanf("%s", name))

Code:

#include <stdio.h> 
int main()
{
    char name[100];
 
    printf("Enter a Name of candidate \n");
    scanf("%s", name);
 
    printf("Name of candidate is  %s\n",name);
	
    return 0;
}

Enter a Name of candidate
Dev
Name of candidate is Dev

when we write scanf in c program we should always write (&) in program. My second program is not correct but why it show the result.

My second program is not correct but why it show the result.

No your second program is correct, it is your assumptions that are wrong. What scanf() expects are addresses of variables and the address of a string is the name of the variable.


By the way your first program is incorrect and your compiler should be warning you about the problems (if you have properly configured your compiler).

Originally Posted by jimblumberg

By the way your first program is incorrect and your compiler should be warning you about the problems (if you have properly configured your compiler).

when I remove address of variable in this program they it doesn't show result and if put Adrress & then it show result

Code:

#include <stdio.h>

 int main()
{
    int Number;
 
    printf("Enter the Number \n");
	
	scanf("%d",Number);
	
	printf("Number is %d",Number);
	
    return 0;
}

when I remove address of variable in this program they it doesn't show result and if put Adrress & then it show result

As I said in my last post scanf() requires an address, you're not providing that required address in your current snippet. Since the variable is not a C-string you need to use the address of operator (&) to pass the address of the variable.

If your compiler was properly configured it should warn you about this problem.