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Java Random nextInt() Method with Example

Random Class nextInt() method: Here, we are going to learn about the nextInt() method of Random Class with its syntax and example.
Submitted by Preeti Jain, on March 23, 2020

Random Class nextInt() method

Syntax:

    public int nextInt();
    public int nextInt(int num);

• nextInt() method is available in java.util package.
• nextInt() method is used to return the next pseudo-random value from this Random Value Generator.
• nextInt(int num) method is used to return the next pseudo-random distribute integer value between 0 and the given parameter (num) from this Random Generator.
• These methods may throw an exception at the time of returning the next integer value.
  IllegalArgumentException: This exception may throw when the given parameter (num<0) is invalid.
• These are non-static methods and it is accessible with the class object and if we try to access these methods with the class name then also we will get any error.

Parameter(s):

• In the first case, nextInt()
  • It does not accept any parameter.
• In the second case, nextInt(int num)
  • int num – represents the last endpoint of this Random Value Generator.

Return value:

In both the cases, the return type of the method is int – it returns next pseudorandom distributed value between 0 and num.

Example:

// Java program to demonstrate the example 
// of nextInt() method of Random

import java.util.*;

public class NextIntOfRandom {
 public static void main(String args[]) {
  // Instantiates Random object
  Random ran = new Random();

  // By using nextInt() method is
  // to return next int pseudo-random
  // value by using Random Value Generator
  int val = ran.nextInt();

  // Display val
  System.out.println("ran.nextInt(): " + val);

  // By using nextInt(int) method is
  // to return next int pseudo-random
  // value between 0 and the given value
  // and 0 is inclusive whereas the given value 
  // is exclusive by using Random Value Generator
  val = ran.nextInt(50);

  // Display val
  System.out.println("ran.nextInt(50): " + val);
 }
}

Output

RUN 1:
ran.nextInt(): -1450643138
ran.nextInt(50): 13

RUN 2:
ran.nextInt(): 1448295644
ran.nextInt(50): 47

RUN 3:
ran.nextInt(): 397396236
ran.nextInt(50): 11