what does {} do in .net? [RESOLVED]

[Andy]

I am looking at the indexof() and one of the examples shows this:

Console.WriteLine("All occurrences of 'he' from position {0} to {1}.", start, [end] - 1)
Console.WriteLine("{1}{0}{2}{0}{3}{0}", Environment.NewLine, br1, br2, str)

what will the output be?



here's the full example:

Dim br1 As String = "0----+----1----+----2----+----3----+----4----+----5----+----6----+-"
      Dim br2 As String = "0123456789012345678901234567890123456789012345678901234567890123456"
      Dim str As String = "Now is the time for all good men to come to the aid of their party."
      Dim start As Integer
      Dim at As Integer
      Dim [end] As Integer
      Dim count As Integer
      
      [end] = str.Length
      start = [end] / 2
      Console.WriteLine()
      Console.WriteLine("All occurrences of 'he' from position {0} to {1}.", start, [end] - 1)
      Console.WriteLine("{1}{0}{2}{0}{3}{0}", Environment.NewLine, br1, br2, str)
      Console.Write("The string 'he' occurs at position(s): ")
      
      count = 0
      at = 0
      While start <= [end] AndAlso at > - 1
         ' start+count must be a position within -str-.
         count = [end] - start
         at = str.IndexOf("he", start, count)
         If at = - 1 Then
            Exit While
         End If
         Console.Write("{0} ", at)
         start = at + 1
      End While
      Console.WriteLine()

[Pirate]

It's just a variable in const string . Consider these examples (test them to understand what actually they do ) :

Private Sub ExampleOne()
        Dim strng As String = "World"
        Console.Write("Hello {0}", strng)
        Console.Read()
    End Sub
 
{0} , this means : include the variable indexed 0 in the paramters list passed to Write method . 
 
    Private Sub ExampleTwo()
        Dim sring1 As String = "VB"
        Dim string2 As String = ".NET"
        Console.Write(" {0}{1} Forums", sring1, string2)
        Console.Read()
    End Sub

{0}{1} , this means : include the variables number 0 and 1 in the paramters list passed to Write method .




They are equal to this :

Private Sub ExampleOne()
        Dim strng As String = "Hello World"
        Console.Write(strng)
        Console.Read()
    End Sub
 
 
    Private Sub ExampleTwo()
        Console.Write("VB.NET Forums")
        Console.Read()
    End Sub

[Andy]

thanks Pirate. I assumed it had something to do like that. I saw another example but it was a LOT harder to understand.

Console.WriteLine("Bill total:" + ControlChars.Tab + "{0,8:c}", billTotal)

I dont understand what the 0, 8:c represents.

another thing, are there any major differences from console.write and .writeline? They apear to do the same job.

[Pirate]

Originally posted by thephantom
thanks Pirate. I assumed it had something to do like that. I saw another example but it was a LOT harder to understand.

Console.WriteLine("Bill total:" + ControlChars.Tab + "{0,8:c}", billTotal)

I dont understand what the 0, 8:c represents.

another thing, are there any major differences from console.write and .writeline? They apear to do the same job.

WriteLine : It writes to the console and stop in the next new line .

Write : Writes to the console and stop where the last character was typed . Consider this example (call one of them at a time )

Private Sub WriteLineTest()
        Console.WriteLine("This uses WriteLine Method")
        Console.Read()
 
    End Sub
 
    Private Sub WriteTest()
        Console.Write("This uses Write Method")
        Console.Read()
    End Sub

[Andy]

oh ok, that makes sense. Thanks alot!!

what about the 8:c part?

[Pirate]

Originally posted by thephantom
what about the 8:c part?

I don't know . What's the output anyway ?

[Andy]

well, don't really know. I had a bit of trouble figuring out how to place the code in my "test" project.

Public Class TipCalculator
   Private Const tipRate As Double = 0.18
   
   'Entry point which delegates to C-style main Private Function
   Public Overloads Shared Sub Main()
      System.Environment.ExitCode = Main(System.Environment.GetCommandLineArgs())
   End Sub
   
   Overloads Public Shared Function Main(args() As String) As Integer
      Dim billTotal As Double
      If args.Length < 2 Then
         Console.WriteLine("usage: TIPCALC total")
         Return 1
      Else
         Try
            billTotal = Double.Parse(args(1))
         Catch
            Console.WriteLine("usage: TIPCALC total")
            Return 1
         End Try
         Dim tip As Double = billTotal * tipRate
         Console.WriteLine()
         Console.WriteLine("Bill total:" + ControlChars.Tab + "{0,8:c}", billTotal)
         Console.WriteLine("Tip total/rate:" + ControlChars.Tab + "{0,8:c} ({1:p1})", tip, tipRate)
         Console.WriteLine("".PadRight(24, "-"c))
         Console.WriteLine("Grand total:" + ControlChars.Tab + "{0,8:c}", billTotal + tip)
         Return 0
      End If
   End Function 'Main
End Class 'TipCalculator

that's what is in the msdn. maybe you can make heads and tails of it?

[Memnoch1207]

where did you see {0,8:c} used???

I've always seen it like this (C# Code)

double billTotal = 15.56;
 
Console.WriteLine("Bill Total: {0:c}", billTotal);

The {0:c} takes the variable billTotal and formats it as currency (c)

[Mike Hildner]

This is all string formatting. When you have {0,8:c}, it's saying this is the 0 index (parameter specifier). The ,8 is the alignment component, and the c (as already stated) is the format string component.

The alignment component allows one to specify the preferred width of the field.

Search MSDN for "Composite Formatting"

[Andy]

Thanks mike! the msdn is great WHEN you know what to look up!!