Given the following code:
string a = "example"; string b = "blah {0}", a; I was led to believe that using {0} or {1}, that it would put whatever is after the comma, in this case string a, so "example". String b should be "blah example". When I do this I get the error "string a is already declared".
Why does it think that I'm declaring a string in this context?
I believe you are intending to use string.Format. It's not implied (but it would be nice).
string b = string.Format("blah {0}", a); Your code would translate like below. The compiler error is obvious when you expand it out fully.
// Given string a = "example"; string b = "blah {0}", a; // corresponds to ... string a; a = "example"; string b; b = "blah {0}"; string a; This line:
string b = "blah {0}", a; declares string b with an initial value, and then declares string a.
When you specify multiple variable names separated by a comma, it declares them all, e.g.:
string a, b, c, d; You probably meant to use String.Format().
string b = String.Format("blah {0}", a); 
looks like you're trying to use String.Format
string b = String.Format("blah {0}", a); Think of it as a method that builds your string for you. kinda like printf from c/c++
You are re-declaring a.
In c# and many other languages, it's short hand to declare variables using a comma delimeter.
Example:
int x,y,z; // declare three integer variables x y and z You need to use String.Format
string a = "example"; string b = string.Format("blah {0}", a); You are just redeclaring the variable as Eric. J said. Looks like you are trying to connect two strings, so you can use Format function from string class:
string a = "example"; string b = string.Format("blah {0}", a); or you can use an operator +:
string a = "example"; string b = "blah " + a; Good luck ;).
This is what you're looking for:
string b = string.Format("blah {0}", a); string b = string.Format("blah {0}", a);
String.Formatfunction. Alas, C# has no language syntax for string interpolation, cf. Ruby"There are #{apples.count} fruit"or Python"There are %s fruit" % apples.count"