CODEWITHSUNDEEP
vb.netforeachsubstringindexof
LabRat
LabRat

Reputation: 2014

Finding Characters in vb.net string

I have a stack overflow question regarding the following code:

For Each DeltaCharB As Char In DeltaString
    If DeltaCharB = "[" Then
        Dim DeltaIndexB As Integer = TB8.IndexOf("[B|")
        Dim DeltaStringB As String = TB8.Substring(DeltaIndexB + 3, TB8.IndexOf("]", DeltaIndexB + 1) - DeltaIndexB - 3)
        MsgBox(DeltaStringB)
    Else
        'Do nothing
    End If
Next

The issue created is that if the code is run X number of times that the character "[" is found, The string is displayed the same X amount of times in a messagebox.

However I only want to have it processed 1X. I have tried to change the following line but as i expected only one character at a time is permitted.

If DeltaCharB = "[B|" Then

Typically the string used to search in would be as follows:

{[A|Text belonging to entry A][B|Text belonging to entry B][C|Text belonging to entry C]}.... ect...ect

Dose anybody know how to resolve this?

Upvotes: 0

Views: 1505

Answers (1)

Zohar Peled
Zohar Peled

Reputation: 82474

Why do you need a loop? Your delimiters are well defined, you can just do this:

Function GetContent(byval input as string, byval delimiter as string) as string
    Dim fullDelimiter = "["& delimiter &"|"
    Dim BeginPosition as Integer = input.IndexOf(fullDelimiter)
    if BeginPosition > -1 then
        BeginPosition += fullDelimiter.Length
        Dim EndPosition = input.IndexOf("][", BeginPosition)
        if EndPosition > -1 then
            return input.SubString(BeginPosition, EndPosition - BeginPosition)
        end if
    end if
    return ""
End Function

And the usage:

Dim s as string = "[A|Text belonging to entry A][B|Text belonging to entry B][C|Text belonging to entry C]"

Dim content = GetContent(s, "B")

content now contains "Text belonging to entry B"

Note that with this code, the delimiter can by a string of any length between [ and |.

A more general solution that will fit any input format would mean to also accept the end delimiter in the function:

Function GetContent(byval input as string, byval FromDelimiter as string, byval ToDelimiter as string) as string
    Dim BeginPosition as Integer = input.IndexOf(FromDelimiter)
    if BeginPosition > -1 then
        BeginPosition += FromDelimiter.Length
        Dim EndPosition = input.IndexOf(ToDelimiter, BeginPosition)
        if EndPosition > -1 then
            return input.SubString(BeginPosition, EndPosition - BeginPosition)
        end if
    end if
    return ""
End Function

Upvotes: 3

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