Compare a value against values in a list C#/VB.NET

I have a value that is inserted by the user that i want to compare against a list of decimal values that i have coded in. I want to go through every value in that list to see if that value typed by the user is greater or less than that specific value in list and if so get the index of that value.

For i As Decimal = 0 To values.Count - 1
   If user_textbox.Text > values.item(i) Then
      test.Text = values.IndexOf(i)
   End If
Next i

This is the code i got up to this point, logically i should get the index of the item because the code snatches up the item itself just fine so i know it works, however the indexof command is returning a "-1" value which means it does not find the value in the list.

Could anyone help me out with this?

Give this a try. It finds the FIRST match in the list and does the string to decimal conversion once.

    Dim lookFor As Decimal = 0
    If Decimal.TryParse(user_textbox.Text, lookFor) Then
        For i As Integer = 0 To values.Count - 1
            If lookFor > values.Item(i) Then
                test.Text = values(i).ToString
                Exit For '<<<<<<<<<<<<<<<<<<
            End If
        Next i
    Else
        'error not decimal value
    End If

Well, your loop counter should be a integer, such as

For i As Integer = 0 To values.Count - 1
If user_textbox.Text > values.item(i) Then
test.Text = i
End If
Next i

so, that will fix up your counter/for loop.

However, for above, you need/want/should/good idea to use the index loop counter as the result. Note how we do NOT use Mylist.Indexof(), and it not required.

However, you can use "index of", but you MUST pass a existing value from the list for this to work.

So, you could do it this way:

    test.Text = -1
For Each OneValue As Decimal In MyList
If CType(user_TextBox.Text, Decimal) > OneValue Then
test.Text = MyList.IndexOf(OneValue)
End If
Next

I would "suggest" that the first example would run MUCH faster, since we don't have to re-search and re-find the "OneValue" we just tested out of the list again (using indexOF is high cost CPU wise), since with the first example loop, we already have the "index" of the list with our loop counter.

Since I don't like to use ".count" ? (and prefer for each?)

I'll often write code this way:

    test.Text = -1
Dim iFound As Integer = 0
For Each OneValue As Decimal In MyList
If CType(user_TextBox.Text, Decimal) > OneValue Then
test.Text = iFound
End If
iFound += 1
Next

The For Each saves declare of a variable, but then we had to declare a counter var, so we really don't save much.

Since you not JUST looking to loop over all values? Then I think the first for/next example is fine.

this one:

    test.Text = -1
For i As Integer = 0 To MyList.Count - 1
If CType(user_TextBox.Text, Decimal) > MyList.Item(i) Then
test.Text = i
End If
Next i

After some trial and error, this was the code that ended up working:

For i As Decimal = 0 To values.Count - 1
If user_textbox.Text > values.item(i) Then
test.Text = values.IndexOf(values(i))
End If
Next i

I wasn't passing the actual value in the list, but this will do the trick.