Arrays

[Latanyar]

I'm having a problem with my code so far

public class arraysReversed
{
    public static void main(String[] args)
    {
        // input from user
        Scanner input = new Scanner(System.in);
        
        // Declaring our variables and setting up the array
        double[] values;//Intializing the Array
        values = new double[10];//Assigning 10 integers for the array to hold
        
        //Ask the user to enter 10 integers
        System.out.println("Please enter ten numbers.");
        values = input.nextDouble();
    }
}

It is saying imcompatible types-found double but expected double[]

[KevinWorkman]

Your values variable is an array of doubles. input.nextDouble() returns a single double. That's like saying:
[this group of something] = [a single member of the group]

Which obviously doesn't make sense.

You want to assign a specific index of the array. Something like this:

values[0] = input.nextDouble();

[rohitjava]

The write way to read array from user is :

public static void main(String []arr){
    // input from user
        Scanner input = new Scanner(System.in);

        // Declaring our variables and setting up the array
        double[] values;//Intializing the Array
        values = new double[10];//Assigning 10 integers for the array to hold

        //Ask the user to enter 10 integers
        System.out.println("Please enter ten numbers.");
        //values = input.next
        for(int i=0;i<values.length;i++){
            values[i]=input.nextDouble();
        }

}

thanks
-rohitjava

[Latanyar]

This is what I have so far:

public class arraysReversed
{
    public static void main(String[] args)
    {
        // input from user
        Scanner input = new Scanner(System.in);
        
        // Declaring our variables and setting up the array
        double[] values;//Intializing the Array
        values = new double[10];//Assigning 10 integers for the array to hold
        
        //Ask the user to enter 10 integers
        System.out.println("Please enter ten numbers.");
        for (int i = 0; i<values.length; i++) //for loop to display the values entered
        {
            values[i] = input.nextDouble();
            System.out.println("Value " + i + " is " + values[i]);
        }
        
    
    }
}

It is also asking me to display them in reverse order in which they were read. I am not sure how I would set this formula up.

[Latanyar]

Hi,

just to confirm do you want to print the values in reverse order of what they were entered in. for example 1, 2, 3 into 3, 2, 1

or do you want to print each of the arrays in reverse format, for example 21 into 12, 245 into 542 etc.

It's for the reversed order. Ex. 1, 2, 3 into 3, 2, 1. Thanks

[Tolls]

It is also asking me to display them in reverse order in which they were read. I am not sure how I would set this formula up.

How do you think you should go about printing that array out backwards?

How would you print it out forwards?

[Latanyar]

When I add another for loop it's still printing the values out in correct order.

public class arraysReversed
{
    public static void main(String[] args)
    {
        // input from user
        Scanner input = new Scanner(System.in);
        
        // Declaring our variables and setting up the array
        double[] values;//Intializing the Array
        values = new double[10];//Assigning 10 integers for the array to hold
        
        //Ask the user to enter 10 integers
        System.out.println("Please enter ten numbers.");
        for (int i = 0; i<values.length; i++) //for loop to display the values entered
        {
            values[i] = input.nextDouble();
           System.out.println("Value " + i + " is " + values[i]);
        }
        
        for (int i = 0; i>values.length; i--) //for loop to display integers in reversed order
        {
           values[i] = input.nextDouble();
            System.out.println("Value " + i + " is " + values[i]);
        }
        
    
    }
}

[Latanyar]

How do you think you should go about printing that array out backwards?

How would you print it out forwards?

On my first for loop it shows how I would print it out forwards. On my second for loop, I thought it would print out backwards, but apparently that is wrong.

[Tolls]

To print it out backwards what do you think "i" should be?
That is, which index in the array should you initially point at?

[coyne20]

This works!

import java.util.ArrayList;
import java.util.List;

public class ArraySwap
{

public static void main(String args[])
{
int [] array = {0,1,2,3,4};
List<Integer> intlist = new ArrayList<Integer>();

for(int i = array.length - 1; i >= 0; i--)
{
intlist.add(array[i]); // adds the value of an index into the list
array[i] = 0; // clears the original array with a 0.
}

Object[] temp = intlist.toArray(); // the list is converted into an object array

for(int i = 0; i <= temp.length - 1; i++)
{
array[i] = (Integer) temp[i]; //each index in the list is re-casted
//back to the array.
}

for(int i = 0; i <= array.length - 1; i++)
{
System.out.println(array[i]); //each index
}
}

}

/*
* This piece of code simply takes an array of integers and reverses it with
* the use of a list.
*/

[Tolls]

Nice code dump...or not.
It's not helpful.

And it's one of the more convoluted ways of simply printintg out an array backwards.

[coyne20]

Ok I realise that my code formatting isnt the best. But the code does meet the objective of re-arranging the values in the array in reversed order.

[Tolls]

It's also a code dump.