What does {0} do?

[VB Programmer]

In VB.NET code examples I've repeatedly seen numbers between 2 curly braces,
such as {0}, {1}, etc...

Example:
Dim str As String = String.Format("Days Left : {0}. Current DataTime: {1:u}.
\n String: {2}, Float: {3}", val, DateTime.Now, name, num)

What does this mean?

 

[Patrice]

This is a placeholder. {0} will be replaced by val, {1} by DateTime.Now
etc...

Patrice

 

[Florian Esser]

In VB.NET code examples I've repeatedly seen numbers between 2 curly
braces,

such as {0}, {1}, etc...

Example:
Dim str As String = String.Format("Days Left : {0}. Current DataTime: {1:u}.
\n String: {2}, Float: {3}", val, DateTime.Now, name, num)

What does this mean?

You might want to take a look at
http://msdn.microsoft.com/library/d...f/html/frlrfsystemstringclassformattopic2.asp.

The MSDN Library is, by the way, usually the first place to look when you
have a syntax question

HTH,

--Florian

===================================
If you wish to contact me directly, send your mail to
florian DOT esser AT gmx DOT de

 

[Lau Lei Cheong]

They mean the order of variables to be inserted in the string.

For example if you try String.Format(" A is {0} and B is {1}, but when
exchanged A is {1} and B is {0}, "A", "B") you'll see what I mean.

 

[VB Programmer]

Thanks everyone!

They mean the order of variables to be inserted in the string.

For example if you try String.Format(" A is {0} and B is {1}, but when
exchanged A is {1} and B is {0}, "A", "B") you'll see what I mean.

 

[VB Programmer]

Why do this:
Response.Write(String.Format("First:{0}, Second:{1}", Var1, Var2))

Versus just doing this

Response.Write("First:" & Var1 & ", Second:" & Var2)

?

 

[Hans Kesting]

Why do this:
Response.Write(String.Format("First:{0}, Second:{1}", Var1, Var2))

Versus just doing this

Response.Write("First:" & Var1 & ", Second:" & Var2)

?

1) easier to read (for humans)
2) probably (can anyone confirm?) better performance than pasting together a lot of strings

Hans Kesting

 

[Patrice]

Flexibility. You have just to use "Premier : {0}, second : {1}." for the
French version or you can use "{1} comes after {0}." instead.

Especially if the format string itself is not hardcoded in the application,
it doesn't even require a code change.

Patrice