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Use of var keyword in C#
Use of “var” type in variable declaration

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大家好，

"var keywork它需要显式类型转换，尽可能避免装箱和取消装箱值类型。"

建议使用var关键字而不是显式数据类型吗？

来自Resharper Horizons博客：

It induces better naming for local variables. When you read local variable declaration with explicit type, you have more information at
that moment and something like"IUnitTestElement current" makes sense.
However, when this local variable is used later, you read"current"
which takes some time to figure out the meaning. Using"var
currentElement" makes it easier to read at any place.

It induces better API. When you let compiler deduce type from method return type or property type, you have to have good types in
the first place. When you don't have explicit type in the
initialization expression, you have to have best names for members.

It induces variable initialization. It is generally a good practice to initialize variable in the declaration, and compiler needs
initializer to infer type for local variable declared with"var"
keyword.

It removes code noise. There are a lot of cases, when implicitly typed local will reduce amount of text developer needs to read, or
rather skip. Declaring local variable from new object expression or
cast expression requires specifying type twice, if we don't use"var".
With generics it can lead to a lot of otherwise redundant code.
Another example would be iteration variable in foreach over
Dictionary.

It doesn't require using directive. With var, you don't have explicit reference to type, as compiler infers type for you, so you
don't need to import namespace when you need a temporary variable.

缺点是代码的可读性可能较低。例如线条int myInt = 0;对大多数人来说仍然比var myInt = 0;但这主要是由于多年来我们一直在研究的语法。

var不是数据类型，它只是"语法糖"的意思，"让编译器在编译时推断出要使用的实际类型"。

因此，您只需了解以下类型推断：