Difference between “var” and “object” in C#

Question

Is the var type an equivalent to Variant in VB? When object can accept any datatype, what is the difference between those two?

Answer 1

Beginning in Visual C# 3.0, variables that are declared at method scope can have an implicit type var . An implicitly typed local variable is strongly typed just as if you had declared the type yourself, but the compiler determines the type. The following two declarations of i are functionally equivalent:

var i = 10; //implicitly typed
int i = 10; //explicitly typed

var isn't object

You should definitely read this : C# 3.0 - Var Isn't Object

Answer 2

For more details have a look at http://www.codeproject.com/Tips/460614/Difference-between-var-and-dynamic-in-Csharp

Answer 3

Nope - var just means you're letting the compiler infer the type from the expression used to assign a value to the variable.

It's just syntax sugar to let you do less typing - try making a method parameter of type " var " and see what happens :]

So if you have an expression like:

var x = new Widget();

x will be of type Widget , not object .

Answer 4

其他答案是正确的，我只想补充一点，你可以实际将光标放在'var'关键字上，然后点击F12跳转到推断的类型声明。

Answer 5

Adding to the post.

Parent p = new Parent(); 
Child c  = new Child();//Child class derives Parent class
Parent p1 = new Child();

With above you can only access parent (p1) properties eventhough it holds child object reference.

var p= new Parent();
var c= new Child();
var p1 = new Child();

when using 'var' instead of class, you have access to both the parent and child class properties. it behaves like creating object for child class.

Answer 6

一个区别是Boxing和Unboxing with Object。