In this tutorial we will get a random number between any range using C++ Program.
Before diving the example you shuld know what are srand and rand functions in C++.
srand : This function sets the starting point for producing a series of pseudo-random integers. If srand() is not called, the rand() seed is set as if srand(1) were called at program start. Any other value for seed sets the generator to a different starting point.
rand: This number is generated by an algorithm that returns a sequence of apparently non-related numbers each time it is called. This algorithm uses a seed to generate the series, which should be initialized to some distinctive value using function srand.
C++ Random Number Between 0 and 1:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | #include <time.h> #include <iostream> using namespace std; int main() { cout<<"Random numbers generated between 0 and 1:"<<endl; srand( (unsigned)time( NULL ) ); //for runs 5 times for (int i = 0; i < 5; i++) { cout << (float) rand()/RAND_MAX << endl; } return 0; } |
Output:
1 2 3 4 5 6 7 8 | Random numbers generated between 0 and 1: 0.214892 0.184938 0.865597 0.494872 0.0708076 |
C++ Random Number Between 1 and 9:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 | #include <time.h> #include <iostream> using namespace std; int main() { int lowest = 1; int range = 9; int random_integer; srand( (unsigned)time( NULL ) ); //for runs 5 times for (int i = 0; i < 5; i++) { random_integer = lowest + rand() % range; cout << "Random Number: " << random_integer << "\n"; } return 0; } |
Output:
1 2 3 4 5 6 7 | Random Number: 3 Random Number: 7 Random Number: 3 Random Number: 1 Random Number: 7 |
C++ random number between 1 and 1000:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 | #include <time.h> #include <iostream> using namespace std; int main() { int lowest = 1; int range = 1000; int random_integer; srand( (unsigned)time( NULL ) ); //for runs 5 times for (int i = 0; i < 5; i++) { random_integer = lowest + rand() % range; cout << "Random Number: " << random_integer << "\n"; } return 0; } |
Output:
1 2 3 4 5 6 7 | Random Number: 319 Random Number: 702 Random Number: 662 Random Number: 370 Random Number: 160 |
C++ random number between 1 and 6:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 | #include <time.h> #include <iostream> using namespace std; int main() { int lowest = 1; int range = 6; int random_integer; srand( (unsigned)time( NULL ) ); //for runs 5 times for (int i = 0; i < 5; i++) { random_integer = lowest + rand() % range; cout << "Random Number: " << random_integer << "\n"; } return 0; } |
Output:
1 2 3 4 5 6 7 | Random Number: 1 Random Number: 2 Random Number: 6 Random Number: 4 Random Number: 4 |
C++ random number between 10 and 50:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 | #include <time.h> #include <iostream> using namespace std; int main() { int lowest = 10; int range = 50; int random_integer; srand( (unsigned)time( NULL ) ); //for runs 5 times for (int i = 0; i < 5; i++) { random_integer = lowest + rand() % range; cout << "Random Number: " << random_integer << "\n"; } return 0; } |
Output:
1 2 3 4 5 6 7 | Random Number: 49 Random Number: 12 Random Number: 54 Random Number: 37 Random Number: 35 |
