Copy Java Array and make a duplicate of it

+1 vote

I have an array x which is constantly being updated. Lets say a = [1,4,9,16,25]. I want to make an exact duplicate copy of x and call it y

May 9, 2018 in Java by Daisy
• 8,140 points
1,625 views

3 answers to this question.

0 votes

Java Array Copy Methods

Object.clone()Object class provides clone() and as we know, an array in java is also an Object, we can use this method to achieve full array copy. Note: This method will not suit you if you want partial copy of the array.

Arrays.copyOfRange()If only few elements of an array are to be copied, where starting index is not 0, you may use this method to copy partial array.

System.arraycopy()System class arraycopy() is the best way to do partial copy of an array. It provides you an easy way to specify the total number of elements to copy and the source and destination array index positions. For example

 System.arraycopy(source, 3, destination, 2, 8) 

will copy 8 elements from source to destination, beginning from 3rd index of source to 2nd index of destination

Arrays.copyOf(): If you want to copy first few elements of an array or full copy of array, you can use this method. It is used due to its simplcity

answered May 9, 2018 by sharth
• 3,370 points
0 votes

You can use System.arraycopy().

int[] src  = new int[]{1,2,3,4,5};
int[] dest = new int[5];
System.arraycopy( src, 0, dest, 0, src.length );
answered Jul 25, 2018 by Akrati
• 3,190 points
0 votes
int[] a = {1,2,3,4,5};
int[] b = Arrays.copyOf(a, a.length);
int[] c = a.clone();

//What if array a comes as local parameter? You need to use null check:

public void someMethod(int[] a) {
    if (a!=null) {
        int[] b = Arrays.copyOf(a, a.length);
        int[] c = a.clone();
    }
}
answered Aug 30, 2018 by Sushmita
• 6,920 points

Related Questions In Java

0 votes
2 answers

What is the use of toString method in Java and how can I use it ?

Whenever you require to explore the constructor ...READ MORE

answered Aug 23, 2018 in Java by Daisy
• 8,140 points
4,048 views
0 votes
2 answers

How to create a 2-D array in java?

int[][] multi = new int[5][]; multi[0] = new ...READ MORE

answered Jul 16, 2018 in Java by Daisy
• 8,140 points
1,345 views
0 votes
2 answers

How can I create File and write data in it using Java?

import java.io.BufferedWriter; import java.io.IOException; import java.nio.file.Files; import java.nio.file.Paths; public class WriteFiles{ ...READ MORE

answered Jul 26, 2018 in Java by samarth295
• 2,220 points
2,834 views
0 votes
1 answer

Is it possible to run a java program from command line on windows?How?

  Let's say your file is in C:\myprogram\ Run ...READ MORE

answered Apr 18, 2018 in Java by sophia
• 1,400 points
2,578 views
+1 vote
1 answer

Are arrays equivalent to objects in Java ?

Yes; the Java Language Specification writes: In the Java ...READ MORE

answered May 10, 2018 in Java by Rishabh
• 3,620 points
1,253 views
+1 vote
1 answer

Remove objects from an array in Java?

We can use external libraries: org.apache.commons.lang.ArrayUtils.remove(java.lang.Object[] array, int ...READ MORE

answered Jun 26, 2018 in Java by scarlett
• 1,290 points
1,146 views
+1 vote
3 answers

What is the syntax to declare and initialize an array in java?

You can use this method: String[] strs = ...READ MORE

answered Jul 25, 2018 in Java by samarth295
• 2,220 points
3,443 views
0 votes
2 answers

What is the syntax to initialize an array?

Rather than learning un-Official websites learn from ...READ MORE

answered Aug 2, 2018 in Java by samarth295
• 2,220 points
894 views
0 votes
1 answer

How to convert a string representation of a hex dump to a byte array using Java?

public static byte[] hexStringToByteArray(String s) { ...READ MORE

answered Sep 26, 2018 in Java by sharth
• 3,370 points
2,051 views
0 votes
2 answers

Get all the permutations of a string in Java

You could use recursion to do this.  Try ...READ MORE

answered Aug 21, 2019 in Java by Sirajul
• 59,230 points
2,187 views
webinar REGISTER FOR FREE WEBINAR X
REGISTER NOW
webinar_success Thank you for registering Join Edureka Meetup community for 100+ Free Webinars each month JOIN MEETUP GROUP