Can you use an array for a Switch(case)?

Question

I've started a Uni course and I can't get me head around how to use my array for a switch case. Basically I just need the help with the switch-case, then I can get on with my work. Heres what it looks like so far:

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

namespace Assignment2
{
 class Program
  {
    public const int noOfentries = 6;
    public const int address = 5;
    public static string[,] addressBook = new string[noOfentries, address];//
    string array for the address book
    public static int deletion;
    public static int choice;
    public static ConsoleKeyInfo keyPressed;
    public static short curItem = 0, c;
    public static string[,] menuItems = new string[,]
    { 
        {"Add Entry"},
        {"Delete Entry"},
        {"Print Book to Screen"},
        {"Edit Contact"}, 
        {"Exit"} 
    };


    #region addEntry
    #endregion
    #region deleteEntry
    #endregion
    #region seeBook
    #endregion
    public static void fourthChoice()
    {
        Console.WriteLine("Would you like to edit the name or address?");

    }

    public static void menu()
    { 
        for (int i = 0; i < 5; i++)
        {
            Console.WriteLine(menuItems[i,0].PadRight(10));
            Console.Clear();
            for (c = 0; c < menuItems.Length; c++)
            {
                if (curItem == c)
                {
                    Console.Write(">");
                    Console.WriteLine(menuItems[c,0]);
                    Console.ForegroundColor = ConsoleColor.Green;
                }

                else
                {
                    Console.WriteLine(menuItems[c,0]);
                }
            }
            Console.WriteLine("Please select an option with the Arrow Keys");
         }
    }
    public static void entries()
    {
        switch (menuItems[0,0])
        {
            case "Add Entry":
                break;
            case "Delete Entry":
                break;
            case "Print Book to Screen":
                break;
            case "Edit Contact":
                break;
            case "Exit":
                break;

        }
    }

and what problem did you encounter? Have you actually tried it? — BrokenGlass, Nov 30 '11 at 13:40
What is the exact problem with the switch case statement, what are you trying to do? — Purplegoldfish, Nov 30 '11 at 13:42
Well im doing a project for uni that is an address book, we have three seperate stages. Im trying to go ahead in stage 2 by using the arrow keys to select the Add, edit, delete and exit options. It might have worked but i cant go into the option by pressing enter, Ive got the `code` Else if (Key.KeyChar.ToString() == "Enter") `code` — user1073429, Nov 30 '11 at 14:06

score 3 · Answer 1 · answered Nov 30 '11 at 13:41

3

There are two aspects to a switch/case:

The value you're switching on
The cases you want to branch to

The fact that you're getting the value from an array is irrelevant. It's equivalent to:

string value = menuItems[0, 0];
switch (value)
{
}

Your cases are also constant string values, so that's fine too. (There's duplication there leading to fragile code which you may want to address, but that's a separate matter.)

... and that's fine. It's not really clear what problem you're having at the moment, although it's also unclear why you've got a rectangular array at all, given that you've only got a single "column" per row. Why not just:

public static string[] menuItems = new string[]
{ 
    "Add Entry",
    "Delete Entry",
    "Print Book to Screen",
    "Edit Contact", 
    "Exit"
};

(Leaving aside naming, accessibility, mutability etc.)

answered Nov 30 '11 at 13:41

Jon Skeet

1,421,763
867
9,128
9,194

Cheers Jon, I think i will re-do this, I used the Rectangle array becasue i saw it on the internet and they used switch case with it. – user1073429 Nov 30 '11 at 13:45
2

@user1073429: It's really important to *understand* the code you're writing. It can be tricky with advanced APIs etc, but I would encourage you to learn C# as a *language* thoroughly - before you "accept" any sample code that you find elsewhere, understand how it works and see if there are alternatives which would work better in your situation. – Jon Skeet Nov 30 '11 at 13:47
That would be good, it should really be the teacher at my uni as this is my first year. It would be nice to learn it from another person. – user1073429 Nov 30 '11 at 13:52

score 3 · Answer 2 · answered Nov 30 '11 at 13:41

3

You should use an Enum for that:

private Enum myEnum { Add, Delete, Edit }

void main(myEnum state)
{
    switch (state)
    {
       Add: //do things
            break;
       Edit: //do things
            break;
       Delete: //do things
               break;
    }
}

answered Nov 30 '11 at 13:41

hcb

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1
18
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I need the text to display, is there a way i can link the enums to the text? – user1073429 Nov 30 '11 at 13:46
here: http://stackoverflow.com/questions/1167361/how-do-i-convert-an-enum-to-a-list-in-c this shows how you can convert enums to an array or list – hcb Nov 30 '11 at 13:49
Ive tried the code above and i cant get the add function in the switch statement? – user1073429 Nov 30 '11 at 14:01
if you have the enum, just type "switch (state)" and press the TAB key twice. Then you'll see it's "myEnum.Add" instead of just "Add" – hcb Nov 30 '11 at 14:31
wait, it's "switch", then double TAB, then add the enum variable (like state) in the generated code, then "arrow down" and it automatically generates all enum values as cases. – hcb Nov 30 '11 at 14:35
It worked but now i cant use my arrow keys to select my options. – user1073429 Dec 01 '11 at 16:11
I've changed the switch case from using text to controls. – user1073429 Dec 01 '11 at 18:06

Can you use an array for a Switch(case)?

2 Answers2