Coffee Time exercise from c# dictionary, hint 🤔

Question

Hey i see that this quest have hint "use coffee.Keys.ToArray() inside foreach loop" but i dont understand why. I tried to solve this quest and i pass but i put coffe.Keys.ToArray() outside foreach loop how is possible to use it inside?

int discount = Convert.ToInt32(Console.ReadLine());

Dictionary<string, int> coffee = new Dictionary<string, int>();
coffee.Add("Americano", 50);
coffee.Add("Latte", 70);
coffee.Add("Flat White", 60);
coffee.Add("Espresso", 60);
coffee.Add("Cappuccino", 80);
coffee.Add("Mocha", 90);

string[] coffeName = coffee.Keys.ToArray();
foreach(string key in coffeName)
{
Console.WriteLine("{0} : {1}",key,Math.Round(coffee[key]*(Convert.ToDouble(100-discount)/100),MidpointRounding.AwayFromZero));

}
Console.ReadKey();

Answer 1

Mr Wolfy, I'm using the following loop => foreach (string c in coffee.Keys.ToArray()){

//performing calculations

}

Answer 2

foreach (string s in coffee.Keys.ToArray())
{
coffee[s] -= (coffee[s]*discount)/100;
Console.WriteLine(s+": "+coffee[s]);
}

Answer 3

Did the same of Wolfy with this inside
coffee[s] -= (coffee[s]*discount)/100;

Answer 4

wow many interesting and complicated calculations but I just want to add mine;
///////////////
foreach (string cf in coffee.Keys.ToArray())
{
a = coffee[cf] * discount;
a = a / 100;
coffee[cf] -= a;
Console.WriteLine("Value; {0}", coffee[cf]);

}

Answer 5

its simple and easy
foreach(string s in coffee.Keys){
int a = coffee[s]- coffee[s]*discount/100;
Console.WriteLine(s+":"+" "+a);

Answer 6

O thanks i didnt know that i can use ToArray() in this way :o

Answer 7

This is a nice challenge. I completed it similar to you guys and it passed example 1 and 2 but failed example 3 which is locked. So I can't see what is what. I pasted in the code at the top for fun. It's showing failing all 3 test cases despite having the right output. I think this one is bugged.

Answer 8

foreach(KeyValuePair<string, int> entry in coffee)
{
Console.WriteLine(entry.Key +": "+(entry.Value-entry.Value*discount/100));
}

Answer 9

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

namespace SoloLearn
{
class Program
{
static void Main(string[] args)
{
int discount = Convert.ToInt32(Console.ReadLine());

Dictionary<string, double> coffee = new Dictionary<string, double>();
coffee.Add("Americano", 50);
coffee.Add("Latte", 70);
coffee.Add("Flat White", 60);
coffee.Add("Espresso", 60);
coffee.Add("Cappuccino", 80);
coffee.Add("Mocha", 90);

//your code goes here
foreach (string s in coffee.Keys.ToArray())
{
coffee[s] -= (coffee[s]*discount)/100;
Console.WriteLine(s+": "+coffee[s]);
}
}
}
}