Problems with array

Question

Hi Everyone I have this: [code] using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; namespace VendingMachineApp { public partial class Form1 : Form { VendorMachine vendorMachine; public String[] snacks = { Cookie Bubble gum Prefzels Soda }; string line = has been dispended; int choose; int i; public Form1() { InitializeComponent(); } private void button1_Click(object sender EventArgs e) { string[] snacks = new string[4]; snacks[0] = Cookie; snacks[1] = gum; snacks[2] = Prefzels; snacks[3] = soda; switch (snacks[choose]) { case snacks[0] :txtOutput.Text = snacks[0] + line; break; case snacks[1]: txtOutput.Text = snacks[1] + line; break; case snacks[2]: txtOutput.Text = snacks[2] + line; break; case snacks[3]: txtOutput.Text = snacks[3] + line; break; default: break; }//end swicth } } } [/code] but what has to be for the case? case snacks[1] - then I get an error: A constant value is expected. I just want if user put an 1 in a textbox that u get as outcome: gum and for 2 - outcome: prefzels. THX

Vulpes · Answer

That's because you haven't set the 'choose' variable which therefore still has its default value of 0. You need to insert this line before you enter the switch statement: int.TryParse(txtChoose.Text out choose); If an invalid number is entered in the textbox then 0 will be used instead. To make sure that choose is within bounds you could also add these lines: if (choose choose = 0; else if (choose > 3) choose = 3;

albert albert · Answer

THX. Yes I will do the exception handling now

albert albert · Answer

Hi Vulpes I had that  but then the problem is that only the first line: cookie is shown.For example if u put a 2 in the textbox and press the button u still get cookie back and not Prefzels: switch (choose) { case 0 :txtOutput.Text = snacks[0] +   + line; break; case 1: txtOutput.Text = snacks[1] +   + line; break; case 2: txtOutput.Text = snacks[2] +  + line; break; case 3: txtOutput.Text = snacks[3] +   +line; break; default: break; }//end swicth also for this: txtOutput.Text = snacks[choose];

Vulpes · Answer

The switch statement needs to be coded like this as you can only use constants for the 'case' expressions: switch (choose) { case 0 : txtOutput.Text = snacks[0] + line; break; case 1 : txtOutput.Text = snacks[1] + line; break; case 2 : txtOutput.Text = snacks[2] + line; break; case 3 : txtOutput.Text = snacks[3] + line; break; default: break; }//end swicth Alternatively you could simply do: txtOutput.Text = snacks[choose] + line;