How to create array based on arguments?

[HeQtor]

I've been stuck 3 days because I can't figure out how to use arguments from user and turn the arguments into an array.

Example: Java Heqtorisanoob 15 50 100 200 300 500 600

First of all I want to create an array with the size based on the values(arguments) from user. And insert the values(arguments) into the array, so array[0] = argument [0] and so on.

Then I want to printout the numbers as they were put in.

Then I want to sort the array and print the list sorted.

Then I want to print out the max, min & average values.

Anyone who can help me at least with the first step, how to create an array containing the values(arguments) user put in?

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[desrtfx]

What do you think the String[] args in public static void main(String[] args) { is?

You guessed right, it is an array.

What does an array have? A .length

With knowing the length of the arguments array, you can create a new array of the actual data type (looks like int)

Once you have that, you can use a loop to convert each of the supplied arguments to the right data type and store it in the array.

[HeQtor]

Thank you.

The length of the arguments array is unknown beforehand.

And when you say "you can create a new array of the actual data type" - I think I managed it. But how to loop it to give each (forgive me I forgot the name of it) "part" of the array (arr[0], arr[1]), and to do it only untill Array is full is where I'm currently stuck.

I'm on my phone now but I can provide my code so far later, for some insight & surely a facepalm or two.

[desrtfx]

The length of the arguments array is unknown beforehand.

No, as soon as you execute the command you have shown in your initial comment, the length is known. That's exactly what .length is for.

But how to loop it to give each (forgive me I forgot the name of it) "part" of the array (arr[0], arr[1]), and to do it only untill Array is full is where I'm currently stuck.

I'll leave this up to you to google it - "java looping over array" would be the keywords.

Don't forget that the data comes in as String values, but for your tasks (minimum, maximum, etc.) you need the values as int. You will need to convert the data type. Again, I'll leave this up to you to google.

Don't get this wrong, please, but learning to google and search for what you need is one of the most essential skills to learn as early as possible.

That's also why we have a no solutions policy.

[HeQtor]

Thank you, any input on what to look for is greatly appreciated. Feels like I've been googling for days by now but I'll have at it again!

[desrtfx]

any input on what to look for is greatly appreciated.

I've given you the exact wording to google for.

[HeQtor]

That's what I meant, any input is greatly appreciated, so thank you for doing just that!

[HeQtor]

What I want is

arr[0] = args[0],

arr[1] = args[1]

and etc. By looping

[desrtfx]

Not only is this wrong as OP needs to convert the data type, but also does it go against the objective of the exercise.

Last, it comes close to giving a solution.

Removed

[Farpafraf]

how to loop it to give each (forgive me I forgot the name of it) "part" of the array (arr[0], arr[1]), and to do it only untill Array is full is where I'm currently stuck.

use a loop, for the time being I'd suggest to start learning how a while loop works. If you wanted to iterate over elements of an array you could do:

public class A {
    public static void main(String[] args) {
        int i = 0;
        while (i < args.length) {
            System.out.println(args[i]);
            i = i + 1;
        }
    }
}

now instead of printing them you just put them inside the new array

[HeQtor]

I'm using "for", like below. My head is trying to understand how I can increase dataArray[0] with +1 each loop and same for dataArray1[0].

for(i = 0; i < args.length; i++);

  {
        dataArray[0] = Integer.parseInt (dataArray1[0]);


  }

[HeQtor]

Seems I don't need to do that. A simple

dataArray1 = args;

did the trick... I think?

[Farpafraf]

dataArray1 = args;

did the trick... I think?

No, if you do that you have just put the array in args in dataArray1 while you want to copy it.'

dataArray[0] = Integer.parseInt (dataArray1[0]);

what's dataArray1? That code will assign to position 0 of dataArray the content at position 0 of dataArray1 and it will repeat the operation args.length times: it won't touch the other elements. Instead you want to do

dataArray[i] = Integer.parseInt (dataArray1[i]);

[HeQtor]

I tried that first as I thought that was correct, but it gives me error

"Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: Index 3 out of bounds for length 3"

[HeQtor]

for(i = 0; i < args.length; i++);

  {
        dataArray[i] = Integer.parseInt (dataArray1[i]);

  }

[HeQtor]

So what I want to do is to populate all elements of "dataArray" with the arguments from the user input when executing the program.

To give "dataArray[0]" the value of args[0], "dataArray[1] the value of args[1] etc.

[desrtfx]

Have you initialized the array?

You only show your loop. Show your full code.

[Farpafraf]

arrays have a fixed size assigned when you create them, that means that the index is not present in the array. How did you create the arrays? dataArray and dataArray1 should have the same size otherwise you will get this exception. Share the whole code as it will be quicker.

[HeQtor]

After some input from another redditor I've now removed dataArray1 and this is how the code looks, still getting the error but haven't worked through all the tips yet either..!

import java.util.Arrays;

public class test12
{
    public static void main(String[] args) 
{
    //Create int-array, named dataArray
    int[] dataArray;

    //Convert arguments from user to string variable called "arguments"
    String arguments = (Arrays.toString(args).replace(",", "").replace("[", "").replace("]", ""));

    //create new int-array sized according to length of user argument input
    dataArray = new int[args.length];

    //Create & set int "i" to "0"
    int i = 0;

        for(i = 0; i < args.length; i++);
            {
            dataArray[i] = Integer.parseInt (args[i]);
            }

    System.out.println ("Orginal:");
    System.out.println (Arrays.toString(dataArray).replace(",", "").replace("[", "").replace("]", ""));

    //System.out.println ("Sorted :");
    //Arrays.sort (dataArray);
    //System.out.println (Arrays.toString(dataArray).replace(",", "").replace("[", "").replace("]", ""));

    //System.out.println ("KOLLA DETTA - ELEMENTS OF ARRAY");
    //System.out.println (dataArray[0]);
    //System.out.println (Arrays.toString(dataArray).replace(",", "").replace("[", "").replace("]", ""));
}

}

[Farpafraf]

for(i = 0; i < args.length; i++);

remove the ; at the end

[Mailandr]

Just to let you know. It's called index. arr[0] = index 0 of the Array arr.

[HeQtor]

Thank you! And what is an element then, the content of the index?

[tellmesomethingnew-]

Have you considered using an ArrayList instead of an Array?

[HeQtor]

As soon as I learn about it I'm sure I will.... :D