VB.net searching for terms within a string?

Question

    Dim keys1() As String = {"corrupt", "selfish", "power", "lying", "lies", "media"}
    Dim terms1 As Integer = 0
    Dim terms1string As String = ""
    terms1string = Console.ReadLine()
    For Each st As String In keys1
        terms1 = terms1 + 1
    Next
    If terms1 < 2 Then
        Console.WriteLine("yay!")
    Else
        Console.WriteLine("YouFail")
    End If

Theres my code. I'd like it to be that if your string entered has more than two of those terms, then it writes "Yay"-- otherwise it writes "YouFail."

---update 8/29/12---

    Function StageTwo(ByVal fname, ByVal lname, ByVal city)
    Console.WriteLine("Describe the U.S. Government.")
    Dim overall As Integer = 0
    Dim keys1() As String = {"corrupt", "selfish", "power", "lying", "lies", "media"}
    Dim terms1 As Integer = 0
    Dim terms1string As String = ""
    terms1string = Console.ReadLine()
    For Each st As String In keys1
        If InStr(terms1string, st) > 0 Then '<<<this line right here!
            terms1 = terms1 + 1
        End If
    Next
    If terms1 < 0 Then
        Console.WriteLine("yay!")
        overall = overall + 1
    End If
    Console.WriteLine()
    Console.WriteLine("Describe the economic status in the U.S.")
    Dim keys2() As String = {"broken", "backed", "failed", "skewed", "tilted", "99%", "rigged", "unfair"}
    Dim terms2 As Integer = 0
    Dim terms2string As String = ""
    terms2string = Console.ReadLine()
    For Each st As String In keys2
        If InStr(terms2string, st) > 0 Then '<<<this line right here!
            terms2 = terms2 + 1
        End If
    Next
    If terms2 < 0 Then
        Console.WriteLine("yay!")
        overall = overall + 1
    End If
    If overall = 2 Then
        Console.WriteLine()
        Console.WriteLine("Enter a username.")
        Dim username As String = ""
        username = Console.ReadLine()
        Console.WriteLine("Please wait.")
        IsURLValid(username, overall)
    Else
        Console.WriteLine("Test Failed.")
    End If
    System.Threading.Thread.Sleep(2000)
End Function

That's my fresh code. Still not working, it's printing test failed after entering corrupt for the first one and broken for the second one. Help again? Thanks so much guys.

Have a look at RegEx. It's a bit of a learning curve, but a definate investment. — Michael Rodrigues
– Michael Rodrigues, Commented Aug 29, 2012 at 4:54

sloth · Accepted Answer · 2012-08-29 07:40:50Z

Why so complicated? Just use Count:

Dim keys1() As String = {"corrupt", "selfish", "power", "lying", "lies", "media"}
Dim terms1string = Console.ReadLine()

Dim terms1 = keys1.Count(function(key) terms1string like "*" & key & "*")

If terms1 < 2 Then
    Console.WriteLine("yay!")
Else
    Console.WriteLine("YouFail")
End If

If you want to match the single words (foobar power lies are 2 matches, foobarpowerlies are 0 matches), you can use this line instead:

Dim terms1 = keys1.Count(function(key) terms1string.Split().Contains(key))

For completeness, here's a regex version:

' generous match ('foobarpowerlies' => 2 matches)
Dim pattern = String.Join("|", keys1)
Dim terms1 = Regex.Matches(terms1string, pattern).Count

or

' strict match using word boundaries ('foobarpowerlies' => 0 matches, but 'foobar power lies' => 2 matches)
Dim pattern = String.Join("|", keys1.Select(function(key) "\b" & key & "\b"))
Dim terms1 = Regex.Matches(terms1string, pattern).Count

Binary Worrier · Accepted Answer · 2012-08-29 08:05:23Z

Should "Austin Powers" match "power" and should "uncorrupt" match "corrupt"? Assuming "no"
Should "POWER" match "power"? Assuming "yes"

The safest way to do this is with Regex

Function WordCount(keys() As String, terms As String) As Integer
    Dim pattern As String = "\b(" + Regex.Escape(keys(0))
    For Each key In keys.Skip(1)
        pattern += "|" + Regex.Escape(key)
    Next
    pattern += ")\b"

    Return Regex.Matches("terms", pattern, RegexOptions.IgnoreCase).Count
End Function


Sub Main()
    Dim keys1() As String = {"corrupt", "selfish", "power", "lying", "lies", "media"}
    Dim count As Integer
    count = WordCount(keys1, "lying son of a corrupt . . .") ' returns 2
    count = WordCount(keys1, "Never caught lying and uncorrupt . . .") ' returns 1
End Sub

The Regex.Escape function ensures that any Regex specific characters in your keys will be escaped, and will not be treated as Regex commands.

The RegexOptions.IgnoreCase option tells it to do a case insensitive match.

The \b is a word boundry, so there must be a word boundary (space, punctuation, new line, start of string, end of string etc) before and after the match.

Putting the keys in this structure (key1|key2|key3) says it can match on key1 or key2 or key3

Hope this helps

SSS · Accepted Answer · 2012-08-29 06:34:56Z

I have something for you.

Your father's INSTR(). This is the weapon of a QuickBasic 4.5 hacker. Not as clumsy or random as a regex; an elegant weapon for a more civilized age.

Module Module1

  Sub Main()
    Dim keys1() As String = {"corrupt", "selfish", "power", "lying", "lies", "media"}
    Dim terms1 As Integer = 0
    Dim terms1string As String = ""
    terms1string = Console.ReadLine()
    For Each st As String In keys1
      If InStr(terms1string, st) > 0 Then '<<<this line right here!
        terms1 = terms1 + 1
      End If
    Next st
    If terms1 < 2 Then
      Console.WriteLine("yay!")
    Else
      Console.WriteLine("YouFail")
    End If
    Console.ReadKey()

  End Sub

End Module

Jim O'Neil · Accepted Answer · 2012-08-29 05:22:49Z

Perhaps too simplistic, but if you use IndexOf, you can change your For loop to:

    If Not String.IsNullOrEmpty(terms1string) Then
        For Each st As String In keys1
            If terms1string.IndexOf(st) <> -1 Then
                terms1 = terms1 + 1
            End If
        Next
    End If

It's simplistic in that it doesn't tokenize the input... so words like "corruption" and "belies" will register a match. If you need exact matches, take a look at String.Split to get the input words, and then there are a number of algorithmic options to compare that list to your list of keys.

Collectives™ on Stack Overflow

VB.net searching for terms within a string?

4 Answers 4

Comments

Comments

Comments

Comments

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

Comments

Comments

Comments

Related