How do I generate random floats in C++?

Samual Sam

Answered 2h 36m ago

In C or C++, we cannot create random float directly. We can create random floats using some trick. We will create two random integer values, then divide them to get random float value.

Sometimes it may generate an integer quotient, so to reduce the probability of that, we are multiplying the result with some floating point constant like 0.5.

Example

#include <iostream>
#include <cstdlib>
#include <ctime>
using namespace std;
main() {
   srand((unsigned int)time(NULL));
   float a = 5.0;
   for (int i=0;i<20;i++)
      cout << (float(rand())/float((RAND_MAX)) * a) << endl;
}

Output

2.07648
4.3115
1.31092
2.22465
2.17292
1.48381
1.91137
0.56505
2.24326
4.44517
3.1695
2.39067
1.89062
4.35881
4.17524
0.189673
1.87521
1.76916
2.3217
2.20481