VB.net searching for terms within a string? - vb.net

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.

Answer 1

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

Answer 2

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

Answer 3

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

Answer 4

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.