For example, if a mutiline textbox has the string "apple" in one of the lines how do I get the line number?
You can use Array.IndexOf:
Dim indexOfText = Array.IndexOf(textBox1.Lines, "apple")
If you want to find a string which can be a part of the line, also searching case-insensitive:
indexOfText = Array.FindIndex(textBox1.Lines, Function(str) str.IndexOf("apple", StringComparison.InvariantCultureIgnoreCase) >= 0)
Since indices are zero based you need to add 1 if you want the line number(in case the index isn't -1).
Another option is to use a RichTextBox which has a GetLineFromCharIndex method which you can use the .Text.IndexOf method to get the index.
Related
I have some information in a list (called listLines). Each line below is in a List(Of String).
1|This is just a header
3|This is just a footer
2|3456789|0000000|12312312313|BLUE|1|35.00
2|7891230|0000000|45645645655|BLUE|1|22.00
2|7891230|0000000|45645645658|RED|2|13.00
2|3456789|0000000|12312312316|RED|2|45.00
2|3456789|0000000|12312312317|YELLOW|5|-9.00
2|3456789|0000000|12312312315|ORANGE|3|15.00
2|7891230|0000000|45645645659|YELLOW|5|32.00
2|3456789|0000000|12312312314|GREEN|4|-20.00
2|7891230|0000000|45645645656|GREEN|4|39.00
2|7891230|0000000|45645645657|ORANGE|3|-18.50
I'm doing a listLines.sort() on the list to sort it alphabetically. Below is what I get after the .sort().
1|This is just a header
2|3456789|0000000|12312312313|BLUE|1|35.00
2|3456789|0000000|12312312314|GREEN|4|-20.00
2|3456789|0000000|12312312315|ORANGE|3|15.00
2|3456789|0000000|12312312316|RED|2|45.00
2|3456789|0000000|12312312317|YELLOW|5|-9.00
2|7891230|0000000|45645645655|BLUE|1|22.00
2|7891230|0000000|45645645656|GREEN|4|39.00
2|7891230|0000000|45645645657|ORANGE|3|-18.50
2|7891230|0000000|45645645658|RED|2|13.00
2|7891230|0000000|45645645659|YELLOW|5|32.00
3|This is just a footer
With that said, I need to output this information to a file. I'm able to do this ok. I still have a problem though. There is a sequence number in the above data at position 5 just after the listed colors (RED, BLUE, ETC..) that you can see. It's just before the last value which is a decimal type.
I need to further sort this list, keeping it in alphabetical order since position 2 is an account number and I want to keep the account numbers grouped together. I just want them to be resorted in sequential order based on the sequence number.
I was looking at another thread trying to figure out how I can do this. I found a piece of code like listLines.OrderBy(Function(q) q.Substring(35)).ToArray. I think this would probably help me if this was a fixed length file, it isn't however. I was thinking I can do some kind of .split() to get the 5th piece of information and sort it but then it's going to unalphabetize and mix the lines back up because I don't know how to specify to still keep it alphabetical.
Right now I'm outputting my alphabetical list like below so I can format it with commas and double quotes.
For Each listLine As String In listLines
strPosition = Split(listLine, "|")
Dim i As Integer = 1
Dim iBound As Integer = UBound(strPosition)
Do While (i <= iBound)
strOutputText = strOutputText & Chr(34) & strPosition(i) & Chr(34) & ","
i += 1
Loop
My main question is how do I re-sort after .sort() to then get each account (position1) in sequential order (position 5)? OR EVEN BETTER, how can I do both at the same time?
The List(Of T) class has an overload of the Sort method that takes a Comparison(Of T) delegate. I would suggest that you use that. It allows you to write a method or lambda expression that will take two items and compare them any way you want. In this case, you could do that like this:
Dim items = New List(Of String) From {"1|This Is just a header",
"3|This Is just a footer",
"2|3456789|0000000|12312312313|BLUE|1|35.00",
"2|7891230|0000000|45645645655|BLUE|1|22.00",
"2|7891230|0000000|45645645658|RED|2|13.00",
"2|3456789|0000000|12312312316|RED|2|45.00",
"2|3456789|0000000|12312312317|YELLOW|5|-9.00",
"2|3456789|0000000|12312312315|ORANGE|3|15.00",
"2|7891230|0000000|45645645659|YELLOW|5|32.00",
"2|3456789|0000000|12312312314|GREEN|4|-20.00",
"2|7891230|0000000|45645645656|GREEN|4|39.00",
"2|7891230|0000000|45645645657|ORANGE|3|-18.50"}
items.Sort(Function(x, y)
Dim xParts = x.Split("|"c)
Dim yParts = y.Split("|"c)
'Compare by the first column first.
Dim result = xParts(0).CompareTo(yParts(0))
If result = 0 Then
'Compare by the second column next.
result = xParts(1).CompareTo(yParts(1))
End If
If result = 0 Then
'Compare by the sixth column last.
result = xParts(5).CompareTo(yParts(5))
End If
Return result
End Function)
For Each item In items
Console.WriteLine(item)
Next
If you prefer a named method then do this:
Private Function CompareItems(x As String, y As String) As Integer
Dim xParts = x.Split("|"c)
Dim yParts = y.Split("|"c)
'Compare by the first column first.
Dim result = xParts(0).CompareTo(yParts(0))
If result = 0 Then
'Compare by the second column next.
result = xParts(1).CompareTo(yParts(1))
End If
If result = 0 Then
'Compare by the sixth column last.
result = xParts(5).CompareTo(yParts(5))
End If
Return result
End Function
and this:
items.Sort(AddressOf CompareItems)
Just note that this is rather inefficient because it splits both items on each comparison. That's not a big deal for a small list but, if there were a lot of items, it would be better to split each item once and then sort based on those results.
The code so far looks like this
For i = 0 To (Len(needed) - 1)
If key.Contains(needed(i)) = False Then
key = key + needed(i)
Else
End If
Within the else I would want to remove all occurrences of the substring key(i) from key except the first one. I could do this using a flag variable within a for loop to gain the location of this and simply replace that with "" however I have the entire alphabet and 3 other characters to check for. Is there a better method to do this???
If you wanted to replace any occurrence of a string except the first one, you could get a substring representing the the string after the first one, and run the replace then.
key.Substring(key.IndexOf(key(i)) + 1).Replace(key(i), "")
Hope this helps.
I have 2 strings as:
STRING 1:
#serial1#code1#true#serial2#code2#false#serial3#code3#true
STRING 2:
#serial1#code1#false#serial2#code2#false#serial3#code3#false
what i need is information(serial1,code1,true/false) for the group for which it is changed. Like in above example i want data only for (serial1,code1,t/f) and (serial3,code3,t/f)
STRING1 is loaded on page_load and STRING2 will be loaded after click of save button. So i want to hit the database for only those values which are changed not for all the values.
Please suggest some suitable logic.
Thanks in Advance.
You can use String.Split() to turn your string into a String Array, and then evaluate the array items.
Example:
strOriginal() = string1.Split("#")
strChanged() = string2.Split("#")
' Assuming both strings had the same number of elements...
For i as Integer = 0 to strOriginal.Length - 1
If strOriginal(i) <> strChanged(i) Then
' Your DB write logic here...
End If
Next
is there a way to count the amount of lines before a specific line / string in a text file.
For Example:
1
2
3
4
5
6
7
8
9
Say i want to count the amount of line before '8'...
How would i do that?
thanks!
Hope that this actually you are looking for,
it will read all lines from a file specified. then find the IndexOf particular line(searchText) then add 1 to it will gives you the required count since index is0based.
Dim lines = File.ReadAllLines("f:\sample.txt")
Dim searchText As String = "8"
msgbox(Array.IndexOf(lines, searchText) + 1)
Here's another example using List.FindIndex(), which allows you to pass in a Predicate(T) to define how to make a match:
Dim fileName As String = "C:\Users\mikes\Documents\SomeFile.txt"
Dim lines As New List(Of String)(File.ReadAllLines(fileName))
Dim index As Integer = lines.FindIndex(Function(x) x.Equals("8"))
MessageBox.Show(index)
In the example above, we're looking for an exact match with "8", but you can make the predicate match whatever you like for more complex scenarios. Just make the function (the predicate) return True for what you want to be a match.
For example, a line containing "magic":
Function(x) x.ToLower().Contains("magic")
or a line that begins with a "FirstStep":
Function(x) x.StartsWith("FirstStep")
The predicate doesn't have to be a simple string function, it can be as complex as you like. Here's one that will find a string that ends with "UnicornFarts", but only on Wednesday and if Notepad is currently open:
Function(x) DateTime.Today.DayOfWeek = DayOfWeek.Wednesday AndAlso Process.GetProcessesByName("notepad").Length > 0 AndAlso x.EndsWith("UnicornFarts")
You get the idea...
Using a List, instead of an Array, is good for situations when you need to delete and/or insert lines into the contents before writing them back out to the file.
This should be fairly simple but I'm having one of those days. Can anyone advise me as to how to replace the first and third occurrence of a character within a string? I have looked at replace but that cannot work as the string could be of different lengths. All I want to do is replace the first and third occurrence.
There is an overload of the IndexOf method which takes a start position as a parameter. Using a loop you'll be able to find the position of the first and third occurences. Then you could use a combination of the Remove and Insert methods to do the replacements.
You could also use a StringBuilder to do the replacements. The StringBuilder has a Replace method for which you can specify a start index and a number of characters affected.
aspiringCoder,
Perhaps something like this might be useful to you (in line with what Meta-Knight was talking about <+1>)
Dim str As String = "this is a test this is a test this is a test"
Dim first As Integer
Dim third As Integer
Dim base As Integer = 0
Dim i As Integer
While str.length > 0
If i = 0 Then
first = str.IndexOf("test")
else if i = 2 Then
third = base + str.IndexOf("test")
end if
base = base + str.IndexOf("test")
str = str.Remove(0, str.IndexOf("test") + "test".length -1 )
i++
End While
It might have a one-off error somewhere...but this should at least get you started.