How to remove an element from an array

Question

In Java, The teacher taught us how to remove an element from an array without using array utils and so on. So I tried the method he gave to us. It updates the index value exactly as I want. after it changes the index value, I want it to delete the last index, "sizeOfArray-1" but I couldn't do that! Any help?

Here the code:

import java.util.Scanner;

public class Arrays {

static int x[] = { 1, 2, 3, 4, 5, 6, 7 };

static Scanner input = new Scanner(System.in);

public int search(int target) {
    for (int index = 0; index < x.length; index++) {
        if (x[index] == target)
            return index;
    }
    return -1;
}

public void deleteIndex(int target) {
    int deleted = search(target);
    if (deleted == -1)
        System.out.println("Entry Not Found!");
    else {
        x[target] = x[7-1];
    }
}

public static void main(String[] args) {
    Arrays f = new Arrays();
    int counteri = 0;
    int counterj = 0;

    for (int j = 0; j < x.length; j++) {
        System.out.print(counterj + "=>" + x[j] + "  \n");
        counterj++;
    }

    f.deleteIndex(input.nextInt());

    for (int i = 0; i < x.length; i++) {
        System.out.print(counteri + "=>" + x[i] + "   \n");
        counteri++;
    }
}
}

It's not a good idea to create new classes with the same name as existing ones i.e. Arrays already exists. — bcsb1001
– bcsb1001, Commented Dec 10, 2014 at 20:24
Create a new array with the specified size you want and fill er' back up! — austin wernli
– austin wernli, Commented Dec 10, 2014 at 20:26
Use an ArrayList.The capacity of an ArrayList van be changed. — Roy Wasse
– Roy Wasse, Commented Dec 10, 2014 at 20:26
Best bet would be to create a new array with one less element, and then use a loop to copy all data from the existing array into the new one, but skip the specified index (that you want to remove) — DerStrom8
– DerStrom8, Commented Dec 10, 2014 at 20:29

Lrrr · Accepted Answer · 2014-12-10 20:39:57Z

1

First of all you have to change this line

x[target] = x[7-1];

to this :

x[deleted] = x[7-1];

because you find an element in your search function, and return its index to deleted so you have to do your action in x[deleted] not x[target]

Your code just replace the actual value of element with amount of last element in here :

else {
    x[target] = x[7-1];
}

So when you want to (so as you call it) delete the last element it just replace last element with it self so it didnot do anything.

You can just simply assign another value that doesnt exist in your array for instance -1 and you could see your function works as you want.

a thing like this :

else {
    x[deleted] = -1;
}

But it is not delete actually, and you cant delete items of array in java.

edited Dec 10, 2014 at 20:39

answered Dec 10, 2014 at 20:30

Lrrr

4,8055 gold badges44 silver badges65 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Lrrr Over a year ago

@Chance if it is your answer, please remember to mark it as answer

Chance Over a year ago

Thank you very much @Ali Amiri, Your answer was very helpful.. I added: int size = x.length; size--;

matsev · Accepted Answer · 2014-12-10 20:25:46Z

1

You really cannot delete an item from an array in Java. Here is some pseudo code that shows what you can do instead:

create a new array that has size -1 of the original array
start looping, keep track of the current index
copy the item(s) from the original array to the new array corresponding to the current index if it should be kept (otherwise skip the item that should be removed)
return the new array

answered Dec 10, 2014 at 20:25

matsev

34k18 gold badges128 silver badges169 bronze badges

1 Comment

bcsb1001 Over a year ago

I will add to this, as the asker appears to be a beginner: use Arrays.copyOf().

aurelius · Accepted Answer · 2014-12-10 22:03:26Z

0

An array in Java has fixed predefined length, once you initialize the array you cannot actually remove an element from it. The best thing you can do is to create another array containing all the elements of the original array without that specific one.

answered Dec 10, 2014 at 22:03

aurelius

4,1149 gold badges43 silver badges78 bronze badges

Comments

Gyana Ranjan Tripathy · Accepted Answer · 2019-06-10 07:36:17Z

//delete the element the perticular element in a position//
import java.util.*;
class main13
{
    public static void main(String args[])
    {
        Scanner sc=new Scanner(System.in);
        System.out.println("Enter the range");
        int no=sc.nextInt();
        System.out.println("Enter the array elements");
        int a[]=new int[no];
        int i,j;

        for(i=0;i<no;i++)
        {
            a[i]=sc.nextInt();
        }
        System.out.println("Enter the element you want to delete");
        int d=sc.nextInt();
        for(i=0;i<no;i++)
        {
            if(d==a[i])
            {
                for(j=i;j<no-1;j++)
                {
                    a[j]=a[j+1];
                }

                break;
            }
            else
            {
                System.out.println("Element not found");
                System.exit(0);
            }
        }
        System.out.println("After deletion:");
        for(i=0;i<no-1;i++)
        {
            System.out.println(a[i]);
        }
    }
}

Collectives™ on Stack Overflow

How to remove an element from an array

4 Answers 4

2 Comments

1 Comment

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

2 Comments

1 Comment

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related