"variable cannot be used as a function" error

[cpsc122]

I'm writing a very simple program, but I keep getting the same error, no matter what I do. What is it that is going wrong? It says I can't use the variable as a function.

Here is my code:

#include <iosrteam>
using namespace std;
int what;
int main()
{
  int what;
  cout << what(9,3,17) << endl;
}
 
int what(int x, int y, int z)
{
    if(x>y && x>z)
      return x;
   if(y>x && y>z)
     return y;
   if(z>x && z>y)
    return z;
  else
   return 0;
}
 

I feel like its a simple fix... help!

[weaknessforcats]

Starting from the top of the program, the first thing the compiler sees is:

int what;

The next thing the compiler sees is:

int main()
 {
 int what;
 

This is a second variable named what but this one is local to main(). The int what outside of main is completely blocked by this local one.

Then the compiler sees:

cout << what(9,3,17) << endl;
 

so you get an error trying to use variable as a function. There is a what function, but the compiler hasn't seen it yet.

YOu need a function prototype:

int what(int x, int y, int z);
 
int main()
{
    what(9,3,17);   // this is now OK
}

The function prototype is the first line of the function definition ended by a semicolon. This tells the compiler there is a function what with 3 int arguments.

Lastly, never name your variables and your functions using the same name.

[MegaCharizardX]

You also wrote #include <iostream> wrong

[Ishan Shah]

You have declared variable which name is the same as the function name, so that's why it will give you an error

int main()
{
  int what;
  cout << what(9,3,17) << endl;
}

if you want to declare the function, then you can write like the following code instead of that

int main()
{
  int what(int,int,int);
  cout << what(9,3,17) << endl;
}
 

[ellavaughn]

thanks for taking the time to explain.

[AjayGohil]

Hi,

In your program you use what as a function and also as a variable and in function declaration there is no parameter and in a function call you pass three parameter.so you have to add three parameter to function declaration.

Thank you