Question

A few months ago I read about a technique so that if there parameters you passed in matched the local variables then you could use some short hand syntax to set them. To avoid this:

public string Method(p1, p2, p3) {     this.p1 = p1;     this.p2 = p2;     this.p3 = p3; } 

Any ideas?

Answer 1

You may be thinking about the new object initializer syntax in C# 3.0. It looks like this:

var foo = new Foo { Bar = 1, Fizz = 'hello' }; 

So that’s giving us a new instance of Foo, with the ‘Bar’ property initialized to 1 and the ‘Fizz’ property to ‘hello’.

The trick with this syntax is that if you leave out the ‘=’ and supply an identifier, it will assume that you’re assigning to a property of the same name. So, for example, if I already had a Foo instance, I could do this:

var foo2 = new Foo { foo1.Bar, foo1.Fizz }; 

This, then, is getting pretty close to your example. If your class has p1, p2 and p3 properties, and you have variables with the same name, you could write:

var foo = new Foo { p1, p2, p3 }; 

Note that this is for constructing instances only – not for passing parameters into methods as your example shows – so it may not be what you’re thinking of.