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I thought this program will print garbage value...Code:#include<stdio.h>
int calsum(int x,int y,int z);
void main()
{
int a,b,c,sum;
printf("\nENter any three numbers\n");
scanf("%d\n%d\n%d",&a,&b,&c) ;
sum=calsum(a,b,c);
printf("\nSum=%d\n",sum);
}
int calsum(int x,int y,int z)
{
int d;
d=x+y+z;
return;
}
but in a compiler C-free : it outputs the value x+y each time and in gcc compiler it gives the value of x+y+z
Can you explain the actual behaviour of the program please.
should be int main, and it should return d correct?
You need to return a value from your function. Try. Otherwise the compiler will return some "random" value.Code:return d;
Jim
Considering you're not returning anything (and you're using void main :(), it should be getting garbage values/runtime error/etc. I don't know about your compiler(s), but it may just be "correcting" you because it thinks you forgot to add a "d" to the return value. And for reference, you could change it to:
It's not any better, just a little cleaner-looking.Code:int calsum(int x,int y,int z)
{
return (x + y + z);
}
Actually I was trying to find out what does it return when I dont specify what to return.
I expected garbage but it gave the correct answer(in gcc, ubuntu. I am not much concerned about the C-free output as I dont know how good compiler it is.)
Can anyone plz explain how the Stack is used to store and clear values between function calls in C. Is it somthing like, the returned value is already at the location pointed to by the return statement by default?
It is undefined behavior, it may work now, but break tomorrow. The compiler will return something, but you can never rely on the value being correct. The value you are getting may be affected by a different compiler, compiler optimizations, and many other things. If you have a function that returns a value, you should always return the correct type of variable. If you don't want a value returned then use a void function.
Jim
Thanlk u all.....