Question about rand and srand

Greetings!

I am new to C++ and I am currently reading jumping into C++ featured on this website. I am reading about the rand and srand functions. The book claims you need a function prototype for these functions however when i input the prototypes my compiler gives me an error untill i comment out the prototypes. Is this expected and if so why? I have copied my code below to give an example with the offending code commented out.

Thank you for your help!

Code:

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#include <iostream>
#include <cstdlib>
#include <ctime>
using namespace std;

int main()
{

//void srand(int x);//function prototype to generate random seed.
//int rand; // function prototype for random number generation.

int random_seed = time( NULL ); // set random seed based on unix clock
srand(random_seed);
cout << rand() << "\n";
cout << rand() << "\n";
cout << rand() << "\n";
cout << rand() << "\n";
}

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The declarations (aka function prototypes) for rand() and srand() are in <cstdlib>.

The declarations you have commented out are in conflict with the declarations in <cstdlib>, hence the compilation errors.

Quote:

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Originally Posted by grumpy

The declarations (aka function prototypes) for rand() and srand() are in <cstdlib>.

The declarations you have commented out are in conflict with the declarations in <cstdlib>, hence the compilation errors.

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grumpy,

Thank you for your time. That makes perfect sense!