&&的链接方法 [英] Chaining methods with &&

问题描述

我有一堆都返回布尔值的方法.

I have a bunch of methods that all return a bool.

如果一个方法返回false，则调用以下方法没有任何价值，尤其是其中一些是昂贵"的操作.

If one method returns false then there is no value in calling the following methods, especially as some of them are 'expensive' operations.

哪个效率更高?

bool result = method1();
if (result) result = method2();
if (result) result = method3();
return result;

或

return method1() && method2() && method3();

据我了解，一旦其中一种方法返回false，对第二种形式应该立即停止评估，对吧?

As I understand it, the 2nd form should stop evaluating as soon as one of the methods returns false, right?

推荐答案

是的，您是对的.均&&&和||c#中的布尔运算符用作短路运算符.确定表达式的值后，它将停止评估表达式.它停止不必要的执行.

Yes you are right. Both && and || boolean operators in c# work as short-circuit operator. It stops evaluating expression once its value is determined. It stops unnecessary execution.

因此，返回方法1()&&method2()&&在您的情况下，method3(); 是更好的选择.如果您有未评估的语句中的某些内容，例如您的情况下说method3，可能会导致一些副作用.

Hence return method1() && method2() && method3(); is better option in your case. If you have something in non-evaluated statement, say method3 in your case, it may lead to some side effects.

Wikipedia 上有一篇关于短路操作员的非常好的语言独立文章.

There is this very good language independent article about short-circuit operators on Wikipedia.

更新:在C#中，如果要使用逻辑运算符而不发生短路，请使用&和|运算符.

UPDATE: In C# if you want to use logical operator without short-circuit, use & and | operator instead.

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