Thread: Random numbers works in one program, not in another

Hello there, I am trying to use random numbers to kind of simulate evolution...with that said I cannot get the random number generator to work when I want.

In one practice program I have this:

Code:

#include <iostream>
#include <windows.h>
#include <conio.h>
#include <string>
//#include <time.h>

using namespace std;

int main(void) {
	
	int num1; 
	srand(GetTickCount());
	num1=rand()%5;
		cout << "Outputting a random number " << num1 << endl;

	return 0;
}

That code works fine for me. However with my human class I have a constructor that tries to initialize all of the attributes to random numbers within 5. It was supposed to be simple but for some reason the numbers are always the same, they nver change. I have tried seeding the random numbers with srand like I did in the previous example but I just can't get random numbers.

Code:

//This is the human program
//The class is class human
//Here is a list of different attritutes to be included:
/*
physical attributes
[pa]
	Hair color, eye color, height, weight, skin color, 
*/
#include <windows.h>
#include <iostream>
#include <string>
#include <conio.h>
#include <time.h>

using namespace std;

class Human {
public:

Human(string name);

void OutPutData();

private:
		string Name;
		int SkinColor,
		HairColor,
		EyeColor, 
		Height, 
		Weight,
		Intelligence;

};

Human::Human(string name) {

	Name = name;
	srand(GetTickCount());
	SkinColor = rand()%5;

	srand(GetTickCount());
	HairColor = rand()%5;

	srand(GetTickCount());
	EyeColor = rand()%5;

	srand(GetTickCount());
	Height = rand()%5;

	srand(GetTickCount());
	Weight = rand()%5;

	srand(GetTickCount());
	Intelligence = rand()%5;
};

void Human::OutPutData()	{
	cout << "Here are the attributes for " << Name << endl;
	cout << "SkinColor " << SkinColor << endl;
	cout << "HairColor " << HairColor << endl;
	cout << "EyeColor " << EyeColor << endl;
	cout << "Weight " << Weight << endl;
	cout << "Height " << Height << endl;
	cout << "Intelligence " << Intelligence << endl;
	};
		
int main(void) {
	
	Human Charles("Charles");

	Human Jessica("Jessica");

	Human Bob("Bob");

	Human Frank("Frank");

	Human Emmy("Emmy");

	Human Rachel("Rachel");

	Charles.OutPutData();
	getch();
	system("cls");


	Jessica.OutPutData();
	getch();
	system("cls");


	Bob.OutPutData();
	getch();
	system("cls");

	Frank.OutPutData();
	getch();
	system("cls");


	Emmy.OutPutData();
	getch();
	system("cls");


	Rachel.OutPutData();
	getch();
	system("cls");

	
	return 0;
}

If you tell me to do a seach on this subject I'm going to be ........ed off, because I already search and I am trying to do what someone else did, but I don't know where I made my mistake.

Oh cool that seems to have worked. Why is it that you only need to call it once. I thought you had to call it every time before you initialized a variable to rand%somenum;

That was short and sweet though.

Is there some way you can do random numbers between some positive number and another positive number (or negative for that matter)

for example x = rand() %10 to 20

Or is that just being silly?

How is it poor form, is it something you just heard or have you actually found out personally why it is poor form. Poor or not it works.

Also fordy, how come you use static void, wouldn't void alone suffice?

I already looked at that, and it doesn't make sense:


"...is poor, because the low-order bits of many random number generators are distressingly non-random"

Which conflicts with the fact that the method I used works fine...I modified the program to output the numbers generated to a text file so I could look all of them over, and they are distinctly random...I can email it to you if you want...