What is the use of randomize and srand functions in C language?

If we are generating random numbers in a program, it is necessary to control the series of numbers.

The randomize() and srand() functions are used to seed the random number generator.

The process of assigning the random number generators starting number is called seeding the generators.

The randomize() uses PC’s clock to produce a random seed.
srand() allows us to specify the random number generator’s starting value.

Program

Given below is the C program on rand −

#include<stdio.h>
int main(){
   // create same sequence of
   // random numbers on every time the program runs
   for(int i = 0; i<10; i++)
      printf(" %d ", rand());
   return 0;
}

Output

You will see the following output −

Following is the C program on srand −

#include <stdio.h>
#include <stdlib.h>
#include<time.h>
int main(){
   // create different sequence of
   // random numbers on every time the program runs
   // It Use current time as seed for random generator
   srand(time(0));
   for(int i = 0; i<10; i++)
      printf(" %d ", rand());
   return 0;
}

Output

You will see the following output −