StringExtensions

StringExtensions

Does

Adds convenient methods to the string class.

Left, Right and Mid

The problem solved

Today's functionality for taking left, right and mid of a string is not as easy as Left$(mystring,length), Right$(mystring,length) and Mid$(mystring,startIndex,length) from the BASIC hey days.

Feel free to take Left, Right and Mid of a string without being afraid of stepping outside the string length as we are with Substr.

"SplitAt".Left(5) => "Split"
"SplitAt".Right(2) => "At"
"SplitAt".Left(100) => "SplitAt"
"SplitAt".Mid(4,2) => "tA"
"SplitAt".Mid(5,100) => "At"
"SplitAt".Mid(6,3) => "itA"

---

SplitAt

The problem solved

Splitting a string is often needed. The built in Split method cannot split at a certain index or with a string as splitter.

Split a string at a certain index.

"SplitAt".SplitAt(5) => [ "Split", "At" ]

Split a string at a certain string.

"SplitAt".SplitAt("it") => [ "Spl", "At" ]

---

string.SFormat that does not crash

This method is losing its value with the adoption of string interpolation.
This method will probably be deprecated.

The problem solved

The normal Microsoft string.Format throws an exception when the {n}s are more than the number of arguments. Throwing an exception might be ok during the development phase but maybe not later on; especially during production when logging to a file. Read this again: If a system is running in production the log files are often the only way to search for problems. We want the logging to log, not throw exception.

string.Format( "We are using {0} many {1}", "too" );

Will throw an exception.

Contrary SFormat

"We are using {0} many {1}".SFormat( "too" );

will render to a We are using {0} many {1}[Failed formatting. Parameter(s) missing. Parameter(s) is/are:{System.String:'too'}.]

We could also solve the above problem with inline string concatenation like so:

"We are using " + "too" + " many " + whatchagot.ToString();

but if one prefers the string.Format way then there is now a safe way to do it. Besides; what happens if whatchagot is null? Exception...

Remaining bugs and caveats

• SFormat does not handle escaped {.
• As long as there is no null dot operator

class MyClass{
    string MyProp{ get; set; }
}
MyClass myObject = null;
"This {0} fail".SFormat( myObject.MyProp );

will fail no matter which method one uses.

Info

log.Error( string.Format( "Method {0} threw an exception with message {1}", methodName ) ); throws an exception. Resharper warns you but without such a tool you will get a string formatting? exception at runtime and the real exception wasn't logged. That is why you have unit tests you might say but 1) do you really have 100% test coverage and 2) if you know the method succeeds no test is needed.

Code

Extensions