Adding an item to a Tuple in C#

Question

I have a tuple array as shown below;

var games = new Tuple <string, Nullable<double>>[] 
                  { new Tuple<string, Nullable<double>>("Fallout 3:    $", 13.95),
                    new Tuple<string, Nullable<double>>("GTA V:    $", 45.95),
                    new Tuple<string, Nullable<double>>("Rocket League:    $", 19.95) };

I am wondering if there is a function would let me add another item to this list.

Please help!

Thanks, Sean

That's not a list, it's an array, so no. If you want a list it would be `List>`. And then you can use it's `Add` method. — juharr, Mar 14 '17 at 12:04
that's not a list... it's an array; the only way to add an item would be through creating a new array from the old one with the additional item — The Bearded Llama, Mar 14 '17 at 12:04
Thanks for the correction (: (i read somewhere it was a list :/). I need to add another item into the array — Tech Dynasty, Mar 14 '17 at 12:06
If the number of elements are going to change at runtime, just don't use an array. Use a list. — Pikoh, Mar 14 '17 at 12:12

score 26 · Accepted Answer · answered Mar 14 '17 at 12:06

26

use List

var games = new List<Tuple<string, Nullable<double>>>()
    {
        new Tuple<string, Nullable<double>>("Fallout 3:    $", 13.95),
        new Tuple<string, Nullable<double>>("GTA V:    $", 45.95),
        new Tuple<string, Nullable<double>>("Rocket League:    $", 19.95)
    };

games.Add(new Tuple<string, double?>( "Skyrim", 15.10 ));

answered Mar 14 '17 at 12:06

Nino

6,931
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Awesome, worked! will mark as answer when it lets me (: – Tech Dynasty Mar 14 '17 at 12:12
1

@TechDynasty On a couple of sidenotes the string in the tuple should just be the game name, you can format the spaces and `$` in later; so far there doesn't seem to be much use to be using a nullable double; the amount should really be a decimal not a double and it would probably be best to use a custom class for this i.e. `Game` – TheLethalCoder Mar 14 '17 at 12:14
1

glad i could help. btw, if your project gets complicated (and it surely will) think of using classes for data instead of Tuples. You'll have cleaner code easier to maintain. – Nino Mar 14 '17 at 12:15

score 2 · Answer 2 · answered Mar 14 '17 at 12:27

Although the other answers already cover what you should be doing i.e. using a List (code taken from this answer):

var games = new List<Tuple<string, Nullable<double>>>()
{
    new Tuple<string, Nullable<double>>("Fallout 3:    $", 13.95),
    new Tuple<string, Nullable<double>>("GTA V:    $", 45.95),
    new Tuple<string, Nullable<double>>("Rocket League:    $", 19.95)
};

And then you can call the Add method:

games.Add(new Tuple<string, double?>("Skyrim:    $", 15.10));

I'd like to point out a few things you can do to improve your code.

The string in the Tuple should just be the game name, you can always format it later:
```
string formattedGame = $"{game.Item1}:    ${game.Item2}";
```
There doesn't seem to be much need for using Nullable<double> (can also be written as double? BTW), consider just using a double.
When dealing with monetary values it is advisable to use decimal, so consider switching to that.
Consider using a custom class i.e. Game. This will simplify the code and help later on when you want to add more details i.e. Description, Genre, AgeRating etc.

For more detail on when to use an array or a list see this question, however, the short version is you should probably be using a list.

AgentFire · Answer 3 · 2017-03-14T12:14:54.933

1

Use Resize method:

Array.Resize(ref games, games.Length + 1);
games[games.Length - 1] =  new Tuple<string, Nullable<double>>("Star Flare: $", 5.00),;

edited Mar 14 '17 at 12:14

answered Mar 14 '17 at 12:08

AgentFire

8,944
8
43
90

1

Needs to be _"Array.Resize(ref games, games.Length + 1);"_ – PaulF Mar 14 '17 at 12:09
2

Although this would work, I would strongly suggest using a `List` in this case – TheLethalCoder Mar 14 '17 at 12:11
List is perfect for this scenario. Array.Resize is an overkill. – Sergey.quixoticaxis.Ivanov Mar 14 '17 at 12:12

score 0 · Answer 4 · answered Mar 14 '17 at 12:11

class Program
{
    static void Main(string[] args)
    {
        var games = new Tuple<string, Nullable<double>>[] 
              { new Tuple<string, Nullable<double>>("Fallout 3:    $", 13.95),
                new Tuple<string, Nullable<double>>("GTA V:    $", 45.95),
                new Tuple<string, Nullable<double>>("Rocket League:    $", 19.95) };

        Array.Resize(ref games, 4);
        games[3] = new Tuple<string,double?>("Test", 19.95);
    }
}

Adding an item to a Tuple in C#

4 Answers4