在这个字符串中，vb.net中的方形刹车是什么意思

Question

What do the square brakets mean in vb.net in this variable below defining as [String]

Dim client As New WebClient()
Dim htmlCode As [String] = client.DownloadString("http://www.stackoverflow.com")

Answer 1

It's useless in your example. Brackets are there to use reserved keywords for what they aren't, for example

Dim [String] = "asdf"

which will create a var named "String" (which is stupid, but...)

Answer 2

It allows you to use a reserved word in your code. There is some mis-information about this as some examples on the MS site use square brackets where they are not needed (In the example you gave the square brackets do not do anything)

As an example I recently wanted to use lat and long as arguments to a function:

Public Function CalcPosition(ByVal lat as Double, ByVal long as Double) as Double

This will not compile because Long is a reserved word but I can do this instead:

Public Function CalcPosition(ByVal lat as Double, ByVal [long] as Double) as Double