Fill an array with random numbers

Question

I need to create an array using a constructor, add a method to print the array as a sequence and a method to fill the array with random numbers of the type double.

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Answer 1

This seems a little bit like homework. So I'll give you some hints. The good news is that you're almost there! You've done most of the hard work already!

• Think about a construct that can help you iterate over the array. Is there some sort of construct (a loop perhaps?) that you can use to iterate over each location in the array?
• Within this construct, for each iteration of the loop, you will assign the value returned by randomFill() to the current location of the array.

Note: Your array is double, but you are returning ints from randomFill. So there's something you need to fix there.

Answer 2

This will give you an array with 50 random numbers and display the smallest number in the array. I did it for an assignment in my programming class.

public static void main(String args[]) {
    // TODO Auto-generated method stub

    int i;
    int[] array = new int[50];
    for(i = 0; i <  array.length; i++) {
        array[i] = (int)(Math.random() * 100);
        System.out.print(array[i] + "  ");

        int smallest = array[0];

        for (i=1; i<array.length; i++)
        {
        if (array[i]<smallest)
        smallest = array[i];
        }



    }

}

}`

Answer 3

You could loop through the array and in each iteration call the randomFill method. Check it out:

import java.util.Random;

public class NumberList {
    private static double[] anArray;

    public static double[] list() {  
        return new double[10];
    }

    public static void print() {
        System.out.println(String.join(" ", anArray));
    }


    public static double randomFill() {
        return (new Random()).nextInt();
    }

    public static void main(String args[]) {
        list();
        for(int i = 0; i < anArray.length; i++)
            anArray[i] = randomFill();

        print();
    }
}

Answer 4

People don't see the nice cool Stream producers all over the Java libs.

public static double[] list(){
    return new Random().ints().asDoubleStream().toArray();
}

Answer 5

Fast and Easy

double[] anArray = new Random().doubles(10).toArray();

Answer 6

You need to add logic to assign random values to double[] array using randomFill method.

Change

 public static double[] list(){
    anArray = new double[10];   
    return anArray;
 }

To

 public static double[] list() {
    anArray = new double[10];
    for(int i=0;i<anArray.length;i++)
    {
        anArray[i] = randomFill();
    }
    return anArray;
}

Then you can call methods, including list() and print() in main method to generate random double values and print the double[] array in console.

 public static void main(String args[]) {

list();
print();
 }

One result is as follows:

-2.89783865E8 
1.605018025E9 
-1.55668528E9 
-1.589135498E9 
-6.33159518E8 
-1.038278095E9 
-4.2632203E8 
1.310182951E9 
1.350639892E9 
6.7543543E7