Generate Random Number : Java Program Code

Random number is an arbitrary number with in the defined range .For example  if we define our range between 1 to 100 , then random number helps to generate any value between 1 and 100.
It can be handy tool in java as many people requires to generate random numbers to make the things  or games look interesting to the audience and also helps to stop the application being hard coded .Otherwise it would have perform in the same manner .
Things to learn here in this code

        array[d] = r.nextInt(32768) ;

//here r is a random class object , and nextInt is a method of random class , so above line point out that
// the value return by nextInt() function will be any between 1 and 32768

Random is the built in class in java which is found in java.util package .

There are many methods in Random class in java which one can use frequently in the java program
Some mostly used functions are :

Function Name            Return Type                            Description

next(int bits)                        int                              Generates the next pseudorandom number .

nextBoolean()                   boolean                        Returns the next pseudorandom uniformly distributed  
                                                                            boolean value from this random number generators seq.

nextDouble()                     double                         It returns the pseudorandom number double value
                                                                            between 0.0 & 1.0                    

nextFloat()                         float                            It returns the pseudorandom number float value between
                                                                            0.0 and 1.0

nextInt()                              int                              It returns the pseudorandom integer value

nextInt(int n)                        int                              It returns the pseudorandom integer value between 0  
                                                                             (included) and n(excluded)

nextLong()                          long                            It returns the pseudorandom long value.

      
There is also a random() method in math class which is in java.math package . Then the natural question arises is that what is the difference in the java.util.random class and java.math random method 
The answer to the question is that the random class in util package can be used to generate any pseudorandom number data type , while the random method in the java.math  is static , thus it always return double value . The double value will always lies between 0.0 (inclusive) and 1.0 (exclusive) .

The important thing to keep in mind while using java.util random class is that we only need one object of random class to generate as many pseudonumbers as we can . We do not need to create the Random class object each time to generate the psedonumbers .

Also , one more point to keep in mind is that the pseudorandom integer value can only be generated in java by using java.util.Random class . Only the object of Random class is capable to generate any integer value . So never use java.math class random method to generate pseudorandom integer values as it always return the double value .


Demo :


Random number java program source code




































Please find the Code below


import java.util.Random;
public class RandomValueLoop
{
    //  generate random numbers and display the largest
    
    public static void main(String args[]){
        Random r = new Random();
        int array [] = new int[10];
        if(array.length==0)
        System.out.print("not possible");
        for(int d = 0; d <array.length; d++){
            array[d] = r.nextInt(32768) ;
        }
        
        int max = array[0];
        System.out.println("Random Array........");
        for( int q = 0; q < array.length; q++ ){
            System.out.println(array[q]);
            if(array[q] > max){
                max =  array[q];
            }
        }
        System.out.println("Maximum Number is: "+ max);
    }
}

About The Author

Subham Mittal has worked in Oracle for 3 years.
Enjoyed this post? Never miss out on future posts by subscribing JavaHungry