Basic C programming question
- by Amit
Hi all, I've just started to learn C and it's going pretty slow...I wanted to write a program that takes in an integer argument and returns it's doubled value (aka take in integer, multiply by 2, and printf that value).
I purposely did not want to use the scanf function. Here's what I have so far and what is not compiling...
#include <stdio.h>
int main(int index)
{
if (!(index)) {
printf("No index given");
return 1;
}
a = index*2;
printf("Mult by 2 %d",a);
return 0;
}
So basically when the program is executed I want to supply the index integer. So, in cygwin, I would write something like ./a 10 and 10 would be stored into the index variable.
Also, I want to program to return "No index given" and exit if no index value was supplied...
Anyone care to help what I'm doing wrong?
EDIT:
This code returns 1 error upon compilation and is based on the help by @James:
#include <stdio.h>
int main(int 1, char index)
{
int index, a;
if (!(index)) {
printf("No index given");
return 1;
}
a = index*2;
printf("Mult by 2 %d",a);
return 0;
}
Thanks!
Amit
