C Reference function srand() initialize random number generator

This function of stdlib will initialize the random number generator that can be used with the rand() function.

Usage of srand():

void srand ( unsigned int seed );

The function srand() is used to initialize the pseudo-random number generator by passing the argument seed.
Often the function time is used as input for the seed.

If the seed is set to 1 then the generator is reinitialized to its initial value. Then it will produce the results as before any call to rand and srand.

Parameters:

An integer value to initialize the random number generator. Often the function time is used as input for the seed.

Return value:

There is nothing returned by srand.

Source code example of srand():


	#include<stdio.h>
	#include<stdlib.h>
	#include<time.h>

	int main ()
	{
		printf ("Our first number: %d\n", rand() % 100);
		srand ( time(NULL) );

		printf ("Some random number: %d\n", rand() % 100);
		srand ( 1 );

		printf ("The first number again: %d\n", rand() %100);

		return 0;
	}

Output of the srand example program above:


	Our first number: 41
	Some random number: 4
	The first number again: 41

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There are currently 4 responses to “C Reference function srand() initialize random number generator”

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  1. Irene QIAN on March 23rd, 2013:

    #include
    #include
    #define ROW_SIZE 50
    #define COL_SIZE 100
    main()
    {
    int i,j;
    int image[ROW_SIZE][COL_SIZE];
    for (i=0;i<ROW_SIZE;i++)
    {
    for(j=0;j0)||(i47)||(i0)||(j97)||(j<99))
    {
    image[i][j]=0;
    }//end if

    } //end else

    printf("%d ", image[i][j]);
    printf("\n");
    }// end for j
    //printf("\n");
    }// end for i

    getchar();
    }// end main

    I don't know how to use the srand()& rand(), so when I run it, only "0"

  2. Vikram Singh on May 7th, 2013:

    I got the ans

  3. Parker Lopuzzo on July 26th, 2013:

    Keep up the good work i will return often.

  4. Mantu Malakar(asansol,westbengal,9851299737) on April 21st, 2014:

    nice explanation …. keep the good works going this will help us a lot as a beginner programmer