Arrays problem with Java

gazzer

Folks.

I am currently doing a Java course and I am spending the weekend looking at arrrays. I have a basic understanding of how to declare them but I am doing out a test question and I need some help as to where I am going wrong.

I have to create an array within a class (called Nim) that represents a group of 3 coins. Each group has a different amount of coins and the class represents a game where there are 2 players and each player takes a certain amount of coins one at a time until there are no coins in any of the groups left.

The first part of code I wanted to input into the class was to declare an instance variable called coinGroup to represent the array so I typed
private int[] coinGroup;

Then i attempted to write a constructor for the class so I typed
public Nim()
{
super();
this.coinGroups = new int[3];
}

This compiled without any errors so then I went into the workspace as requested in the question and I was asked to type the following

int[coins] = {9, 11, 13];
Nim aGame = new Nim(coins);

I did this and executed each line one line at a time. The first line executed fine but when I executed the second line I got the following error
Error: line 1 - constructor Nim in class Nim cannot be applied to given types;
required: no arguments
found: int[]
reason: actual and formal argument lists differ in length

I take it I should have put an argument into the constructor but Im not sure where and what to put so I would really appreciate any help.

Thanks in advance

threein99

gazzer wrote: »

Folks.

I am currently doing a Java course and I am spending the weekend looking at arrrays. I have a basic understanding of how to declare them but I am doing out a test question and I need some help as to where I am going wrong.

I have to create an array within a class (called Nim) that represents a group of 3 coins. Each group has a different amount of coins and the class represents a game where there are 2 players and each player takes a certain amount of coins one at a time until there are no coins in any of the groups left.

The first part of code I wanted to input into the class was to declare an instance variable called coinGroup to represent the array so I typed
private int[] coinGroup;

Then i attempted to write a constructor for the class so I typed
public Nim()
{
super();
this.coinGroups = new int[3];
}

This compiled without any errors so then I went into the workspace as requested in the question and I was asked to type the following

int[coins] = {9, 11, 13];
Nim aGame = new Nim(coins);

I did this and executed each line one line at a time. The first line executed fine but when I executed the second line I got the following error
Error: line 1 - constructor Nim in class Nim cannot be applied to given types;
required: no arguments
found: int[]
reason: actual and formal argument lists differ in length

I take it I should have put an argument into the constructor but Im not sure where and what to put so I would really appreciate any help.

Thanks in advance

You need a constructor to match the call new Nim(coins) , that error you are getting means java is looking for a constructor that takes no parameters, so you need to create a constructor that takes the parameters you require for your game.

counterpointaud

In addition to the above, int[coins] = {9, 11, 13]; is not valid Java syntax as far as I know, should probably be int[] coins = {9, 11, 13];

You have variable name coinGroup, and coinGroups too, I assume these should be the same name ?

gazzer

Thanks for the help folks.

I walked away from the laptop for a bit and when I came back something clicked and I (think) have the correct code.

public class Nim
{
private int[] coinGroups = new int[3];


public Nim(int[] coins)
{
coinGroups = coins;
}
}

When I tested out the code in the workspace it behaved as expected.

Thanks again.