I am trying to perform a Substring function on a image filename.
The name format is in "images.png".
I tried using Substring it only allow me to indicate the first character till the "n" character to perform the function.
Such that SubString(1,6).
But what I want is to get any character before the ..
For example "images.png":
After the Substring function I should get "images".
You can use LastIndexOf in conjunction with Substring:
myString.Substring(0, myString.LastIndexOf('.'))
Though the Path class has a method that will do this in a strongly typed manner, whether the passed in path has directories or not:
Path.GetFileNameWithoutExtension("images.png")
How about using the Path class.
Path.GetFileNameWithoutExtension("filename.png");
In general for such string manipulations you can use:
mystring.Split("."c)(0)
But specifically for getting a filename without extension, it's best to use this method:
System.IO.Path.GetFileNameWithoutExtension
Dim fileName As String = "images.png"
fileName = IO.Path.GetFileNameWithoutExtension(fileName)
Debug.WriteLine(fileName)
http://msdn.microsoft.com/en-us/library/system.io.path.getfilenamewithoutextension.aspx
string s = "images.png";
Console.WriteLine(s.Substring(0, s.IndexOf(".")));
Related
I have this string:
201057&channelTitle=null_JS
I want to be able to cut out the '201057' and make it a new variable. But I don't always know how long the digits will be, so can I somehow use the '&' as a reference?\
myDigits substring(0, position of &)?
Thanks
Sure, you can split the string along the &.
String s = "201057&channelTitle=null_JS";
String[] parts = s.split("&");
String newVar = parts[0];
The expected result here is
parts[0] = "201057";
parts[1] = "channelTitle=null_JS";
In production code you chould check of course the length of the parts array, in case no "&" was present.
Several programming languages also support the useful inverse operation
String s2 = parts.join("&"); // should have same value like s
Alas this one is not part of the Java standard libs, but e.g. Apache Commons Lang features it.
Always read the API first. There is an indexOf method in String that will return you the first index of the character/String you gave it.
You can use myDigits.substring(0, myDigits.indexOf('&');
However, if you want to get all of the arguments in the query separately, then you should use mvw's answer.
I copied code to map a network drive from http://www.vbforums.com/showthread.php?t=616519 to map the drive and http://cjwdev.wordpress.com/2010/05/30/delete-network-drive/ to delete the drive. I want to know what "R"c means in this code:
RemoveNetworkDrive("R"c, True)
which came from the first link and then I want to know how to simulate this notation in a variable so I can check for the first available drive and map the network drive to that letter. I would Google search it but since I don't know what "R"c means it makes it difficult.
"R"c is the Char version of "R". You use it when you want to specify a character rather than a string.
MSDN has some details here:
You can also create an array of strings from a single string by using the String.Split Method. The following example demonstrates the reverse of the previous example: it takes a shopping list and turns it into an array of shopping items. The separator in this case is an instance of the Char data type; thus it is appended with the literal type character c.
Dim shoppingList As String = "Milk,Eggs,Bread"
Dim shoppingItem(2) As String
shoppingItem = shoppingList.Split(","c)
It converts your string "R" to a char, as requested from function
Public Shared Sub RemoveNetworkDrive(ByVal DriveLetter As Char, ...)
It's the syntax for a character literal, basically - it's the equivalent of 'R' in C#, if that makes it any clearer.
Im just wondering if it is possible to put a variable in a pattern match in Lua. Like something similar to the following:
var = "hello"
pattern = string.match(datasource, "(var)%s(a%+)")
The reason I need to do this is because the variable "var" will change periodically. (it will be in a loop)
Cheers in advance
Lua doesn't handle string interpolation inside of the quotes. Instead, you'll need to concatenate the parts with the var as a var reference and the rest as quote strings.
"("..var..")%s(a%+)" starts with a "(" as a string literal, concatenates the variable, then finishes off the rest of the string with a string literal.
Use "("..var..")%s(a%+)" instead.
I needed the same thing I think, a variable in a pattern match, but the above solution didn't work for me. I'm posting my solution in case it helps someone, didn't find anything else on the net like it.
I read a ': ' delimited file (name: tel) and want to search by name in the file and have the name and telephone number as answer.
local FileToSearch = h:read'*a' -- Read all the file
var = io.read() -- ask the name
string.gmatch(FileToSearch, ''..var..': '..'%d+') -- search for name, concatenate with number
I want to have a string in the following format
"FAG001 FAG002 FAG003"
and want to split it into
"FAG001"
"FAG002"
"FAG003"
using a regular expression. Unfortunately my knowledge of regular expression synatax is limited to say teh least. I have tried things like
Dim result = Regex.Split(npcCodes, "([A-Z]3[0-9]3)").ToList
without luck
No need of regex here, you could use String.Split
Dim result As String() = npcCodes.Split(new Char[]{" "})
But if you really want to use regex :
Dim result = Regex.Split(npcCodes, " ").ToList()
As madgnome has pointed out you don't need regular expressions here if the string is always separated with spaces.
However for your information the error you made was that you need curly braces for numeric quantifiers:
[A-Z]{3}
And instead of Regex.Split you can uses Regex.Matches.
The regular expression to use in the Split method would be really simple:
Dim result = Regex.Split(npcCodes, " ").ToList
As the expression only matches a single character, you can just as well use the regular Split method in the String class:
Dim result = npcCodes.Split(" "C).ToList
I'm new to regular expressions, and have no clue where to start, it's like a diff language to me. But I need one quick to accomplish a task.
I need to take
http://www.domain.com/folder1/folder2/file_path.txt
and get just
/folder1/folder2/file_path.txt
from it.
Thanks!
construct a URI object from it and one of the properties of it will have what you want.
I think that regex should work:
^http://.*?/(.*)$
(tested with Python)
Since VB.NET is in the tag for this question, I assume you have access at the server side to the Request object:
Dim instance As HttpRequest
Dim value As String
value = instance.Path
This should give you exactly what you asked for.
Edit: On second thought - you could be parsing URLs from some input string... in which case, regex will only help if you have a simple (regular) set of inputs:
Do you know all the possible domains? i.e. are "http://www.ABC.com" and "http://www.DEF.com" the only possible domains?
Then here:
Dim text As String = "http://www.ABC.com/folder1/folder2/file.txt"
Dim pattern As String = "(?:http://www.ABC.com|http://www.DEF.com)(.*)"
Dim r As Regex = new Regex(pattern, RegexOptions.IgnoreCase)
' Match the regular expression pattern against a text string.
Dim m As Match = r.Match(text)
Dim g as Group = m.Groups(2) 'Gives the string matched by the capturing parentheses
Supporting more protocols and making the protocol optional too.
((https?|ftp)://)?(.*?)/(.*)