Generating a random number in java based on user inputs for max and min

Question

I having a little trouble trying to genertae a radom set of numbers with what the user defines as max and min, I am new to programming and feel a little lost with my code

int upperRange; int lowerRange; Random random = new Random(int)(Math.random()*(upperRange - (lowerRange-1)))+lowerRange; Scanner keyboard = new Scanner(System.in); { System.out.println("Enter upper limit number "); upperRange = keyboard.nextInt(); System.out.println("Enter lower limit number"); lowerRange = keyboard.nextInt(); 

Any help would be appreciated

Answer 1

Where r is an instance of class Random, and x and y are positive integers,

r.nextInt(y - x) + x 

should do what you want. It will give you an integer in the range x (inclusive) to y (exclusive).

Answer 2

Try this:

public class TestRandomBounds { public static void main(String[] args) { int upperBound = 100; int lowerBound = 50; Random random = new Random(); System.out.println(lowerBound + random.nextInt(upperBound - lowerBound)); } } 

Once the random bounds are defined you just need to generate a random number that will reside inside those bounds.

Answer 3

Your code could be written like this:

import java.util.*; public class RandGuess { public static void main ( String[] args ) { int upperRange; int lowerRange; Random random; int randomFromUserLimits; Scanner keyboard = new Scanner(System.in); System.out.print("Enter upper limit number: "); upperRange = keyboard.nextInt(); System.out.print("Enter lower limit number: "); lowerRange = keyboard.nextInt(); random = new Random(); randomFromUserLimits = random.nextInt(upperRange-lowerRange) + lowerRange; System.out.println("A random number between " + lowerRange + " and " + upperRange + " = " + randomFromUserLimits); } }