Strings in

About Strings

The key thing to remember about C# strings is that they are immutable objects representing text as a sequence of Unicode characters (letters, digits, punctuation, etc.). Double quotes are used to define a string instance:

string fruit = "Apple";

Manipulating a string can be done by calling one of its methods or properties. As string values can never change after having been defined, all string manipulation methods will return a new string.

A string is delimited by double quote (") characters. Some special characters need escaping using the backslash (\) character. Strings can also be prefixed with the at (@) symbol, which makes it a verbatim string that will ignore any escaped characters.

string escaped = "c:\\test.txt";
string verbatim = @"c:\test.txt";
escaped == verbatim;
// => true

If you only need a part of a string, you can use the Substring() method to extract just that part:

string sentence = "Frank chases the bus.";
string name = sentence.Substring(0, 5);
// => "Frank"

The IndexOf() method can be used to find the index of the first occurence of a string within a string, returning -1 if the specified value could not be found:

"continuous-integration".IndexOf("integration")
// => 11

"continuous-integration".IndexOf("deployment")
// => -1

Finally, there are many ways to concatenate a string. The simplest one is by using the + operator.

string name = "Jane";
"Hello " + name + "!";
// => "Hello Jane!"

For any string formatting more complex than simple concatenation, string interpolation is preferred. To enable interpolation in a string, prefix it with the dollar ($) symbol.

string name = "Jane";
$"Hello {name}!";
// => "Hello Jane!"