i have a string "<PinX F='53mm'></PinX>", I want to access the 53 within the string and do some addition to it and then add the answer back into that string. I've been thinking about this and wasn't sure whether this can be done with regular expression or not? Can anybody help me out.
thanks
Yes, you can use a regular expression. This will get the digits, parse them to a number, add one to it, and put it back in the string (that is, the result is actually a new string as strings are immutable).
string s = Regex.Replace(
input,
#"(\d+)",
m => (Int32.Parse(m.Groups[1].Value) + 1).ToString()
);
Take a look at the HTML Agility Pack.
A regular expression looks like a good fit for this particular problem:
\d+
Will match one or more digits.
Int32.Parse(Regex.Match("<PinX F='53mm'></PinX>", #"\d+").Value)
Will return 53.
In this single case yes. "'(.*?)' then access the first group, but if this is part of a larger xml regular expressions should not be used. You should utilize the xml parser build into .net find the attribute with xsd and get the value.
Alternatively, here's a small routine...
' Set testing string
Dim s As String = "<PinX F='53mm'></PinX>"
' find first occurence of CHAR ( ' )
Dim a As Integer = s.IndexOf("'")
' find last occurence of CHAR ( ' )
Dim b As Integer = s.LastIndexOf("'")
' get substring "53mm" from string
Dim substring As String = s.Substring(a, b - a)
' get integer values from substring
Dim length As Integer = substring.Length
Dim c As Char = Nothing
Dim result As String = Nothing
For i = 1 To length - 1
c = substring.Chars(i)
If IsNumeric(c) Then
result = result & c
End If
Next
Console.WriteLine(Int32.Parse(result))
Console.ReadLine()
Related
like my title already explained, I want to get a substring of a string (who contains a address) and I would like to have only the street..
It's not possible to only take the text (non-numeric) chars, because then the box will remain.
It's not possible to take substring till first space, because the streetname can contain a space..
For example 'developerstreet 123a' -> would like to have 'developerstreet'
The 'a' is a box number of the house, which I'm not interested in..
How can I do this in VB.NET?
Parsing addresses is notoriously difficult, so I caution you to make sure that you a very deliberate about the choices you make. I would strongly recommend reviewing the documentation provided by the postal service. If these are US addresses, you should start by looking at the USPS Publication 28.
However, to answer your specific question, you can find the index of the first numeric character in a string by using the Char.IsDigit method. You may also want to take a look at the Char.IsNumber method, but that's probably more inclusive than what you really want. For instance, this will get the index of the first numeric character in the input string:
Dim index As Integer = -1
For i As Integer = 0 to input.Length - 1
If Char.IsDigit(input(i)) Then
index = i
Exit For
End If
Next
However, for complex string parsing, like this, I would suggest learning Regular Expressions. Getting the non-numeric portion at the beginning of a string becomes trivial with RegEx:
Dim m As Match = Regex.Match(input, "^\D+")
If m.Success Then
Dim nonNumericPart As String = m.Value
End If
Here is the meaning of the regular expression in the above example:
^ - The matching string must start at the beginning of the line
\D - Any non-numeric character
+ - One or more times
try this:
Private Sub MyFormLoad(sender As Object, e As EventArgs) Handles Me.Load
Dim str As String = "developerstreet 123a"
Dim index As Integer = GetIndexOfNumber(str)
Dim substr As String = str.Substring(0, index)
MsgBox(substr)
End Sub
Public Function GetIndexOfNumber(ByVal str As String)
For n = 0 To str.Length - 1
If IsNumeric(str.Substring(n, 1)) Then
Return n
End If
Next
Return -1
End Function
output will be: developerstreet
text.Substring(0, text.IndexOfAny("0123456789"))
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.
I got this url for example "http://www.yellowpages.com/manhattan-beach-ca/mip/marriott-manhattan-beach-4933923?lid=185795402"
I want to get the last digit numbers and the rest could be anything.
I need a format like this "http://www.yellowpages.com/anything.... lid=randomdigitnumbers" or as long as i get those numbers.
My knowledge is very poor in this regex thing so please guys help me.
the following did not work
Dim r As New System.Text.RegularExpressions.Regex("http://www.yellowpages.com/.*lid=d*", RegexOptions.IgnoreCase)
Dim m As Match = r.Match(txt)
If (m.Success) Then
Dim int1 = m.Groups(1)
MsgBox("(" + int1.ToString() + ")" + "")
End If
thank you in advance
Using Regular Expressions for this is a bit of overkill, IMO.
You could accomplish the same thing using string functions:
Dim url As String = "http://www.yellowpages.com/manhattan-beach-ca/mip/marriott-manhattan-beach-4933923?lid=185795402"
Dim queryString As String = url.SubString(url.IndexOf("?"), url.Length - url.IndexOF("?"))
Dim nameValuePairs As String() = queryString.Split("=")
Dim lid As String = nameValuePairs(1)
This is off the top of my head, so you may need to tweak it a bit. The basic concept is to the portion of the URL after the ? (the query string), and then split it on the = sign, taking the second element of the resulting array (the value).
Also, if the query string has more than one name value pair, they'll be separated by &, so you'll need to split on the ampersand (&) first, then the equal signs.
Just find lid= and get everything after that:
Dim url As String = "http://www.yellowpages.com/manhattan-beach-ca/mip/marriott-manhattan-beach-4933923?lid=185795402"
Dim lidIndex As Integer = url.IndexOf("lid=") + "lid=".Length
Dim lid As Integer = url.Substring(lidIndex)
I need to split one variable into 3 variables. For example I have a variable called Data and it contains AAA00000001. I need to have them be split between the "AAA", "0000000", and "1". I looked at the Split() function but didn't get a clear example for this situation. The reason I need to do this is because I want to store these 3 variables into fields for a MySQL database.
Are the three subvariables always of the same length?
If so, you can use Substrings:
Dim substring1 As String = Data.Substring(0, 3)
Dim substring2 As String = Data.Substring(3, 7)
Dim substring3 As String = Data.Substring(10, 1)
Assuming the string is ALWAYS the EXACT same length and need to be split at the SAME place, you can use Substring().
dim s as String = "AAA00000001"
dim s1 as String = s.Substring(0, 3)
dim s2 as String = s.Substring(3, 7)
dim s3 as String = s.Substring(10)
If they're not always the same length, you're probably going to need to use Regular Expressions.
Split will break your string apart based on a character, or group of. It's not appropriate here, that is unless you're always splitting on 0000000, which I doubt you are.
If you know that the first 3 characters will always be your first group, second 7 your next, and last character, your final group, you could do something like this.
This uses the Substring function, e.g.
Dim yourString as String = "AAA00000001"
Dim c1 As String = yourString.Substring(0, 3)
Dim c2 As String = yourString.Substring(3, 7)
Dim c3 As String = yourString.Substring(10, 1)
Dim phoneNumber As String = "077 47578 587(num)"
How do i strip the above string off every character which isnt a number. So only the numbers are left and then check to make sure it is 11 characters long?
dim number as string = Regex.Replace(phoneNumber,"[^0-9]","")
if number.length = 11 then
'valid number
else
'not valid
end if
You could loop on each character and check if it is a digit. While looping, check that the number of accepted characters (digits) is less than 11.
or
use a regex to remove all the alpha but you still will have to count at the end ....
Dim phoneNumber As String = "077 47578 587(num)"
Dim newPhoneNumber = String.Empty
For i = 0 To phoneNumber.Length - 1
If IsNumeric(phoneNumber(i)) Then
newPhoneNumber += phoneNumber(i)
End If
Next
Dim valid = newPhoneNumber.Length = 11
One possible solution is to treat the string as a character array, then retrieve only those characters with ascii codes within the paramaeters you define.
Ascii codes can be found at a resource such as: http://www.bolen.net/html/misc/ASCII-codes.html
Alternatively, you could use a regular expression to retrieve only the characters you want. My regex isn't so hot, so I can't give an example :)