adding more than 2 numbers

[tintincute]

hello

I wrote a program where I can add the items and if it's more than 250 Euro, 10% discount will be given.

I've used the "if-statement" and I just started only with two numbers. Now, I would like to add as many as I can, is there a way and I would like that the program will stop if there's nothing to add more.

I've researched in Google but it seems I can't find topics on how to deal with it, maybe you guys have an idea. It will be great appreciated.

Thanks, below is my code I made:

This is what I've done:

double firstValue;
double secondValue;
double theSumValue;

Console.WriteLine("The price of the first item:");
firstPrice = Convert.ToDouble(Console.ReadLine());

Console.WriteLine("The price of the second item:");
secondPrice = Convert.ToDouble(Console.ReadLine());

theSumValue = firstPrice + secondPrice;

if(theSumValue >= 250)
theSumValue *= 0.9;

Console.WriteLine("The final value in Euro is " + theSumValue);

[Dhaneshnm]

use a while loop to get values.Then use an array list to store those values.use another loop to get the sum.your problem will be solved.

[ddanbe]

Your code, as you posted it will not work.
Try and get a look at this:

using System;
using System.Collections;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            //An ArrayList can store any number of items via the Add method
            ArrayList Prices = new ArrayList();

            //initialize the total price
            double theSumValue = 0.0;

            //Enter prices and store them in an ArrayList
            Console.WriteLine("Enter the number of prices:");
            int NumberOfPrices = Convert.ToInt32(Console.ReadLine());
            for (int i = 0; i < NumberOfPrices; i++)
            {
                Console.WriteLine("Enter the price of item {0}:", i+1);
                Prices.Add(Convert.ToDouble(Console.ReadLine()));
            }

            //Calculate sum
            foreach (double d in Prices)
            {
                theSumValue += d;
            }

            //Add reduction if needed
            if (theSumValue >= 250.0)
                theSumValue *= 0.9;

            Console.WriteLine("The final value in Euro is {0} ." ,theSumValue); 

            //Keep the console on screen
            Console.WriteLine("Press any key to quit.");
            Console.ReadKey();
        }
    }
}

Be aware that this is kept as simple as possible, no error checking is done here etc.

[tintincute]

hello ddanbe,

thank you for your reply. I did try the code but I'm getting an error.

"Error 1 The type or namespace name 'ArrayList' could not be found (are you missing a using directive or an assembly reference?)"

do I need to create here an additional namespace?

thank you and regards

[ddanbe]

If you add using System.Collections; it should work.

[tintincute]

hi thanks, i tried it but it didn't work.
i'm not sure if i have to configure here.

[thoughtcoder]

That's a pretty weird error. What are you using to build and run things?

[tintincute]

hi it worked. I thought the using.System.Collections.Generic is already the same as using.System.Collections. That's why. But then I tried adding it at the end then it work. I just need to rename some of the variables because it sounds quite different.
like: "Enter the number of prices". I changed it to "Enter the number of items:"
thoughtcoder, thanks. I'm using microsoft visual c# 2008 and trying the examples in the console application.

by the way I would like to know why, do I have to add the "using System.Collections;" what is the reason behind?

thanks for your help again;-)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;

[tintincute]

hi again,
i would like to know why do I have to add the "using System.Collections;" what is the reason behind?

thanks again
regards

[thoughtcoder]

ArrayList is in the System.Collections namespace and List<> is in the System.Collections.Generic namespace. Use List<double> instead of an ArrayList, and use System.Collections.Generic instead of System.Collections. There's no reason to use obsolete collection types here.

[tintincute]

i see the ArrayList and the System.Collections are already obsolete?
but are they also part of C#?

thanks

[thoughtcoder]

Yes. You can still use them. They're not formally obsolete -- they aren't going away.

But it's better to use List<double> because that gives you better type safety and makes your code easier for others to read.

[tintincute]

Yes. You can still use them. They're not formally obsolete -- they aren't going away.

But it's better to use List<double> because that gives you better type safety and makes your code easier for others to read.

thanks. if i use the List<double> is my code correct here:
btw what does the via the Add Method here means?

//An ArrayList can store any number of items via the Add method
List<double> Prices = new List<double>();

//initialize the total price
double theSumValue = 0.0;

[dickersonka]

Prices.Add(2.0);

This only appends to your list, this does not so called 'add' or sum them together

for the sum you need to use a foreach or enumerator as you had before, and increment sumValue