CODEWITHSUNDEEP
c#syntax
Nikola Luburic
Nikola Luburic

Reputation: 153

Can someone explain this syntax in C#?

When creating objects in Java I'm used to the following syntax:

objectX1 = new ObjectX(some arguments);

While looking over a project in C# I came across the following code:

_createSample = new Func<SampleBase>[]
{
    () => new SkeletonMappingSample();
}

I need two things explained to me. First, how does creating an object without the brackets and parameter list and instead using {} with expressions work?

Next, what does the expression between the {} mean?

Upvotes: 0

Views: 164

Answers (2)

mathieu
mathieu

Reputation: 31202

This code creates an array of Func : _createSample = new Func<SampleBase>[]

Then it instantiates one lambda expression () => new SkeletonMappingSample() as the sole element in it, using collection initializer (note the braces, and the semicolon is optional): 

{
    () => new SkeletonMappingSample();
}

This expression will instantiate a new SkeletonMappingSample when called :

var newMappingSample = _createSample[0]();

Upvotes: 1

Clint
Clint

Reputation: 6220

The code you found:

_createSample = new Func<SampleBase>[]
{
    () => new SkeletonMappingSample();
}

Is just a notation for creating an array and then initialising it with values.

Which is effectively the same as:

_createSample = new Func<SampleBase>[1];
_createSample[0] = () => new SkeletonMappingSample();

Except that in the { } version the bounds are set by the compiler based on how many elements you've added between the { }

For objects:

SomeClass abc = new SomeClass()
{
   SomeProperty = "SomeValue",
}

Is just a way of creating an object and then setting some property values, it's effectively the same as:

SomeClass abc = new SomeClass();
abc.SomeProperty = "SomeValue";

Upvotes: 3

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