Create enum class to assign Index

Question

I get a string from input ,I want to give it a index like the following:

For example:

string Name = "Jack"

There are 5 possibilities :

Jack   = 1, 
Alice  = 2,
Stiven = 3,
Alex   = 4,
Katrin = 5

when I get Name from input I want to go through this enum class and get the index of it

do you have this enum declared? if so please post the code. Or what do you mean by " this enum class " ? — Mong Zhu, Apr 06 '18 at 12:20
Enums are not meant to store data like this; there are better data structures for this case. — Sebastian Hofmann, Apr 06 '18 at 12:22
you don't know how to declare an enum? Here is the [documentation](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/enum) — Mong Zhu, Apr 06 '18 at 12:23
@SebastianHofmann can you tell me how to write it with Dictionary? — papagallo, Apr 06 '18 at 12:24
@MongZhu I know,but for example its not possible to write Mong Zhu=1,does not accept the space between — papagallo, Apr 06 '18 at 12:24
The title is create an enum and the accepted answer is with a dictionary? — Slaven Tojić, Apr 06 '18 at 12:54

score 6 · Accepted Answer · edited Apr 06 '18 at 12:29

6

Use a dictionary better, they are exactly meant to store a value corressponding to a given object.

Dictionary<string, int> dict = new Dictionary<string, int>() { 
  {"Jack", 1 }, {"Alice", 2 }, {"Steven", 3 }, {"Alex", 4 }, {"Katrin", 5 }};

string name = "Jack";

int value = dict[name]; // returns 1

edited Apr 06 '18 at 12:29

Dmitry Bychenko

180,369
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answered Apr 06 '18 at 12:25

M Bakardzhiev

632
5
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3

or `if (dict.TryGetValue(name, out var value)) {/* name found its index is value */} else { /* not found */}` – Dmitry Bychenko Apr 06 '18 at 12:31

score 1 · Answer 2 · answered Apr 06 '18 at 12:25

you can try Enum.TryParse, following way :-

string Name="Jack";
enum CustomEnum {
  Jack=1,
  Alice=2,
  Stiven=3,
  Alex=4,
  Katrin=5
}

CustomEnum TheName;
if (Enum.TryParse(Name, out TheName))
{
    switch (TheName) { 
      case Jack: /* code here*/ break;
      case Alice: /* code here*/ break;
      /* and so on */
    }
}

score 1 · Answer 3 · answered Apr 06 '18 at 12:29

Try this.

using System;

public class Test {
 enum Names {
  Jack = 1,
   Alice,
   Stiven,
   Alex,
   Katrin
 };
 public static void Main() {

  string Name = "Alex";
  Names eName;
  Enum.TryParse < Names > (Name, out eName);
  Console.WriteLine((int) eName);
 }
}

Demo here : https://ideone.com/ArhV67

score 1 · Answer 4 · answered Apr 06 '18 at 12:30

1

First declare an enum:

enum Names
{
    Jack = 1,
    Alice = 2,
    Stiven = 3,
    Alex = 4,
    Katrin = 5
}

and then use Enum.TryParse to get the enum that matches "Jack", at the end cast myNames to int to get the desired index :

string Name = "Jack";
Names myNames;
Enum.TryParse(Name, out myNames);
int index = (int)myNames;

answered Apr 06 '18 at 12:30

Slaven Tojić

2,945
2
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You don't need to declare `myNames` earlier, that's the advantage of `out`. You can simply do: `Enum.TryParse(Name, out Names myNames);` – L. Guthardt Apr 06 '18 at 12:34
@L.Guthardt I tried it your way but it doesn't work. I'am using Visual Studio 2015 – Slaven Tojić Apr 06 '18 at 12:37
`TryParse` does return a `bool` that represents if the parsing did work or not. – Cleptus Apr 06 '18 at 12:42
@bradbury9 I know that it returns a bool but i didn't assing it to a variable because i don't have to use it. I use TryParse to avoid exceptions – Slaven Tojić Apr 06 '18 at 12:45
@SlavenHvar Have a look at the [MSDN about out](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/out-parameter-modifier). It is possible to instantiate the parameter in the *method parameter section*. – L. Guthardt Apr 06 '18 at 13:50
@L.Guthardt your way works only with C# 7. I am using Visual studio 2015 where new features of C#7 don't work. I tried your examples and it won't compile – Slaven Tojić Apr 06 '18 at 13:58
@SlavenHvar Ok, I somehow missed that you wrote you are using VS2015. – L. Guthardt Apr 06 '18 at 14:02
@L.Guthardt no problem. Thanks for the info anyway. – Slaven Tojić Apr 06 '18 at 14:04

Create enum class to assign Index

4 Answers4