Trim
This VB.NET function removes leading and trailing whitespace. String
data often has leading or trailing whitespace characters—newlines, spaces or tabs.
Characters like spaces at the end or start are usually not needed. With Trim
we strip these characters in a declarative way. Other program logic may become simpler.
This code references a string
literal that contains leading spaces and a trailing space. Next the Trim
Function is invoked, and a new string
is allocated on the managed heap.
string
returned by the Trim
Function does not contain the leading spaces or trailing space.Module Module1 Sub Main() ' Input string. Dim value As String = " This is an example string. " ' Invoke Trim function. value = value.Trim() ' Write output. Console.Write("[") Console.Write(value) Console.WriteLine("]") End Sub End Module[This is an example string.]
Text files may have unnecessary spaces or tab characters. If you read in a file line-by-line you can then trim these lines and process them with simpler logic.
Imports System.IO Module Module1 Sub Main() ' Read in the lines of a file. For Each line As String In File.ReadAllLines("data.txt") ' The existing line. Console.WriteLine("[{0}]", line) ' Trimmed line. Dim trimmed As String = line.Trim() Console.WriteLine("[{0}]", trimmed) Next End Sub End Module[ Something] [Something] [Example ] [Example] [ Another] [Another]
Dictionary
A Dictionary
can store string
keys and reference data objects as values. It is a good idea to trim input before passing it to a Dictionary
lookup method.
The Trim
Function clears excess leading and trailing whitespace characters from string
data. With Trim
we more easily accept input from users and files.