Member Avatar for RaoxFaello

I'm trying to create a program that determines if what i inputted is a Literal (String or a Char)
My idea on how to create one is if i inputted a string (Starts with the usual ") so the first Index in my Array should be " or else it will show invalid same with the last index it should be ".

So my problem is i don't know how. If i input something in a Textbox (Example: Daniweb) my program should automatical determine that an Array has 6 indexes, Can someone help me.

Edited by RaoxFaello
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Dani AI

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Quick summary and clarification (ties to the replies by , and ): treat the TextBox content as a sequence of characters. The number of elements equals the number of characters you actually want to store; because VB uses zero‑based indexing the last index is length − 1. So the literal text Daniweb contains 7 characters and its highest index is 6 (array length 7, indexes 0..6). The community hints — check the first/last character and view a string as a character sequence — are the right starting points.

A practical checklist and pitfalls to handle reliably:

  • Trim accidental outer whitespace but don’t lose spaces intentionally inside quoted literals.
  • If the user typed a quoted literal, remove the surrounding quotes to get the inner content before counting characters.
  • Support common literal forms: VB char literal uses a quoted character followed by c (for example: "a"c), C#/JS char style uses single quotes ('a'), and string literals use double quotes ("text"). Verify the inner content length for char literals (usually one character).
  • Watch malformed input: unmatched quotes, empty quotes, or multi-character content with a trailing c should be treated as invalid or plain text depending on desired behavior.
  • If full language-literal parsing is required (escaped quotes, Unicode escapes), use a small parser or a regex tuned for the target escape rules rather than only checking first/last characters.

Example helper (VB.NET): this routine classifies the input, returns the kind and the character count / last index for the inner content.

Function AnalyzeInput(input As String) As Tuple(Of String, Integer, Integer)
    If String.IsNullOrEmpty(input) Then Return Tuple.Create("Empty", 0, -1)
    Dim s = input.Trim()
    Dim dq As Char = ChrW(34) ' "
    Dim sq As Char = "'"c      ' '
    ' VB char: "x"c
    If s.Length >= 4 AndAlso s(0) = dq AndAlso (s(s.Length - 1) = "c"c OrElse s(s.Length - 1) = "C"c) AndAlso s(s.Length - 2) = dq Then
        Dim inner = s.Substring(1, s.Length - 3)
        If inner.Length = 1 Then Return Tuple.Create("Char", 1, 0)
    End If
    ' C#-style char: 'x'
    If s.Length >= 3 AndAlso s(0) = sq AndAlso s(s.Length - 1) = sq Then
        Dim inner = s.Substring(1, s.Length - 2)
        If inner.Length = 1 Then Return Tuple.Create("Char", 1, 0)
    End If
    ' Double-quoted string
    If s.Length >= 2 AndAlso s(0) = dq AndAlso s(s.Length - 1) = dq Then
        Dim inner = s.Substring(1, s.Length - 2)
        Return Tuple.Create("String", inner.Length, Math.Max(-1, inner.Length - 1))
    End If
    ' Plain text
    Return Tuple.Create("Plain", s.Length, Math.Max(-1, s.Length - 1))
End Function

Note: this is a pragmatic helper. If input must accept escaped sequences (e.g. \" or doubled "" in VB), extend the routine with a parser or regex that understands those escapes.

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Member Avatar for Ancient Dragon

Use substr() method e.g. if textBox1.Text.Substring(0,1) = '"' then

Member Avatar for RaoxFaello

Thanks for replying but i have one problem, It's not dynamic.
What if i type something that has larger numbers and letters and the one in the code is fixed it will give me Invalid.

Edited by RaoxFaello
Member Avatar for tinstaafl

Use the Textbox1.Text.Length property.

Any string is basically a character array. You can read the individual characters with an index, Textbox1.Text(0). The last character, without using LINQ, like this, Textbox1.Text(TextBox1.Text.Length-1). With LINQ, TextBox1.Text.Last().

A simple conditional statement to test, If Not(TextBox1.Text(0) = """"c) Or Not(TextBox1.Text(TextBox1.Text.Length-1) = """"c) Then.

Edited by tinstaafl
Member Avatar for RaoxFaello

Thank you every much.
I was so fixed on using something more complicated like what i've suggested with the indexes and arrays
whereas i didn't even know there's a Property like that, I really need to read more.

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