Colon Uses in C#: Chain Constructors

August 20, 2019

Colon

In C# Language

StackOverflow - In C# what category does the colon “ : ” fall into, and what does it really mean?
C# Corner - Constructor Chaining In C#

I was reading over some C# code and came across a weird use of a colon and decided to look into some of its uses to get a better understanding of when it is being used. The stack overflow answer I came across was the most inclusive and helpful for looking into it more, as it described the colon as a "simple syntactic symbols, like [] or {}" as opposed to being a type of operator.

The case I was looking at using the colon appeared to be a chain constructor setup. A colon can be used to call another constructor (or the base constructor class) prior to the current one. This led to the next link when I searched for more help on constructor chaining.

Examples:

public Foo() : base() { }

public Foo(int bar) : this() { }

public class mySampleClass
{
public mySampleClass(): this(10)
{
// No parameter constructor method.// First Constructor
}

public mySampleClass(int Age)
{
// Constructor with one parameter.// Second Constructor}
}
}