为什么喜欢var strList = new List< string>（）; over list< string> strList = new List< string>（）;? [英] Why prefer var strList = new List<string>(); over List<string> strList = new List<string>();?

问题描述

为什么在创建对象时，最好使用 var 关键字比真实类型？

Why when creating object it is preferred to use var keyword than real type?

var strList  = new List<string>(); //good?
List<string> strList  = new List<string>(); //why bad?

问题不仅仅是列表< T> 。

推荐答案

不是 var 一个是坏的。

如果你想让我更具体，我想你应该使用 var 当类型完全明显时，例如：

If you want me to be more specific, I think you should use var only when the type is completely evident, such as:

var employee = new Employee();

另一方面，这可能是一个可怕的想法：

On the other side it's probably a horrible idea to do:

var e = GetEmployees();

因为很难判断 e 是 Employee 对象或List，数组等。

Because it's hard to tell whether if e is an Employee object, or a List, array, etc.

在不降低可读性的情况下节省您一些工作：

Also is probably right to use it when it saves you some effort while not diminishing readability:

ReallyLongClassName someidentifier = new ReallyLongClassName();

VS

var explanatoryIdentifier = new ReallyLongClassName();

但最终，这归结于个人喜好，只是 / strong>如果您损害了可读性，请保存一些字符。

But at last, it comes down to be personal preference, just don't ever save you some characters if you are damaging readability.

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