Java Array Exercises: Shuffle a given array of integers

Java Array: Exercise-60 with Solution

Write a Java program to shuffle a given array of integers.

Input :
nums = { 1, 2, 3, 4, 5, 6 }
Shuffle Array: [4, 2, 6, 5, 1, 3]

Sample Solution:

Java Code:

import java.util.Arrays;
import java.util.Random;

class solution
	public static void shuffle(int nums[])
		for (int i = nums.length - 1; i >= 1; i--)
			Random rand = new Random();

			int j = rand.nextInt(i + 1);

			swap_elements(nums, i, j);
        private static void swap_elements(int[] nums, int i, int j) {
		int temp = nums[i];
		nums[i] = nums[j];
		nums[j] = temp;
	public static void main (String[] args)
		int[] nums = { 1, 2, 3, 4, 5, 6 };
        System.out.println("Original Array: "+Arrays.toString(nums));
		System.out.println("Shuffle Array: "+Arrays.toString(nums));

Sample Output:

Original Array: [1, 2, 3, 4, 5, 6]
Shuffle Array: [4, 2, 6, 5, 1, 3] 


Flowchart: Shuffle a given array of integers

Java Code Editor:

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Java: Tips of the Day

Different between parseInt() and valueOf() in java?

Well, the API for Integer.valueOf(String) does indeed say that the String is interpreted exactly as if it were given to Integer.parseInt(String). However, valueOf(String) returns a new Integer() object whereas parseInt(String) returns a primitive int.

If you want to enjoy the potential caching benefits of Integer.valueOf(int), you could also use this eyesore:

Integer k = Integer.valueOf(Integer.parseInt("123"))

Now, if what you want is the object and not the primitive, then using valueOf(String) may be more attractive than making a new object out of parseInt(String) because the former is consistently present across Integer, Long, Double, etc.

Ref: https://bit.ly/3vRuIPY