反转＆QUOT;若＆QUOT;语句来减少嵌套 [英] Invert "if" statement to reduce nesting

问题描述

当我跑 ReSharper的我的code，例如：

When I ran ReSharper on my code, for example:

    if (some condition)
    {
        Some code...            
    }

ReSharper的给了我上述警告（反转if语句，以减少嵌套），并提出以下更正：

ReSharper gave me the above warning (Invert "if" statement to reduce nesting), and suggested the following correction:

   if (!some condition) return;
   Some code...

我想明白为什么那最好不过。我始终认为，在方法问题的中间使用回归，有点像转到。

I would like to understand why that's better. I always thought that using "return" in the middle of a method problematic, somewhat like "goto".

推荐答案

在方法中间的返回不一定是坏事。它可能会更好，如果它使code更清晰的意图，立即返回。例如：

A return in the middle of the method is not necessarily bad. It might be better to return immediately if it makes the intent of the code clearer. For example:

double getPayAmount() {
    double result;
    if (_isDead) result = deadAmount();
    else {
        if (_isSeparated) result = separatedAmount();
        else {
            if (_isRetired) result = retiredAmount();
            else result = normalPayAmount();
        };
    }
     return result;
};

在此情况下，如果 _isDead 是真实的，马上就可以摆脱的方法。它可能会更好，而不是这种方式构建的：

In this case, if _isDead is true, we can immediately get out of the method. It might be better to structure it this way instead:

double getPayAmount() {
    if (_isDead)      return deadAmount();
    if (_isSeparated) return separatedAmount();
    if (_isRetired)   return retiredAmount();

    return normalPayAmount();
};   

我从重构目录选择这个code。这种特殊的重构称为：与保护条款替换嵌套条件

I've picked this code from the refactoring catalog. This specific refactoring is called: Replace Nested Conditional with Guard Clauses.

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