difference between initializing an object with these two ways in c# [duplicate]

Question

generally i instant initialize an object when adding it to a list with this way --->

list.add(    new foo() {                       //     <--- foo()       field1 = value1,       field2 = value2     } ); 

but once i just tried --->

list.add(    new foo {                     //     <--- foo       field1 = value1,       field2 = value2     } ); 

& it worked !!!

in the 2nd way i am just creating an object without using () at tail of it. so does anyone have any idea about the difference between these various ways to initializing an object ?

Answer 1

so does anyone have any idea about the difference between these various ways to initializing an object ?

There's no difference at all. In both cases you're using an object initializer, and if you don't specify any constructor arguments, that's exactly equivalent to providing an empty list of constructor arguments. From section 7.6.10.1 of the C# spec:

An object creation expression can omit the constructor argument list and enclosing parentheses provided it includes an object initializer or collection initializer. Omitting the constructor argument list and enclosing parentheses is equivalent to specifying an empty argument list.

Note that when you just invoke a constructor without using an object initializer (the braces) you have to specify the constructor arguments. So:

Foo foo = new Foo();    // Valid Foo foo = new Foo;      // Invalid Foo foo = new Foo() {}; // Valid Foo foo = new Foo {};   // Valid 

The "valid" lines are all exactly equivalent, including any use of default parameters - so Foo might only have a constructor like this:

// You can invoke this without specifying arguments public Foo(int x = 0) { } 

See section 7.6.10 of the C# 5 spec for more details.

Answer 2

They are both object initializers. There is no difference. It's a good question though. I would think that behind the scenes the result is the same.... Compiler creates object with empty constructor and sets properties.