是否有充分的理由说明在函数中只有一个return语句是一个更好的实践?

或者在逻辑上正确的情况下,可以从函数中返回,这意味着函数中可能有许多返回语句?


当前回答

总是要求单一的返回类型是没有意义的。我认为这更像是一个标志,表明某些东西可能需要简化。有时有多个回报是必要的,但通常你可以通过至少尝试有一个退出点来简化事情。

其他回答

对于足够小的函数来说,多个出口点很好——也就是说,可以在一个屏幕长度上完整地查看函数。如果一个冗长的函数同样包含多个出口点,则表明该函数可以进一步分割。

也就是说,除非绝对必要,否则我避免使用多出口功能。在更复杂的函数中,由于一些模糊的行中出现的一些错误返回,我感到了错误的痛苦。

你知道有句谚语——情人眼里出西施。

有些人信得过NetBeans,有些人信得过IntelliJ IDEA,有些人信得过Python,有些人信得过PHP。

在一些商店,如果你坚持这样做,你可能会丢掉工作:

public void hello()
{
   if (....)
   {
      ....
   }
}

这个问题完全是关于可见性和可维护性。

I am addicted to using boolean algebra to reduce and simplify logic and use of state machines. However, there were past colleagues who believed my employ of "mathematical techniques" in coding is unsuitable, because it would not be visible and maintainable. And that would be a bad practice. Sorry people, the techniques I employ is very visible and maintainable to me - because when I return to the code six months later, I would understand the code clearly rather seeing a mess of proverbial spaghetti.

嘿,伙计(就像一个前客户曾经说过的),做你想做的,只要你知道如何在我需要你解决它的时候解决它。

I remember 20 years ago, a colleague of mine was fired for employing what today would be called agile development strategy. He had a meticulous incremental plan. But his manager was yelling at him "You can't incrementally release features to users! You must stick with the waterfall." His response to the manager was that incremental development would be more precise to customer's needs. He believed in developing for the customers needs, but the manager believed in coding to "customer's requirement".

我们经常因为打破数据规范化、MVP和MVC边界而感到内疚。我们内联而不是构造函数。我们走捷径。

就我个人而言,我认为PHP是一种糟糕的实践,但我又知道什么呢?所有的理论争论都归结为试图满足一套规则

质量=精度,可维护性 和盈利能力。

所有其他规则都退居幕后。当然,这条规则永远不会消失:

懒惰是一种美德 程序员。

Well, maybe I'm one of the few people here old enough to remember one of the big reasons why "only one return statement" was pushed so hard. It's so the compiler can emit more efficient code. For each function call, the compiler typically pushes some registers on the stack to preserve their values. This way, the function can use those registers for temporary storage. When the function returns, those saved registers have to be popped off the stack and back into the registers. That's one POP (or MOV -(SP),Rn) instruction per register. If you have a bunch of return statements, then either each one has to pop all the registers (which makes the compiled code bigger) or the compiler has to keep track of which registers might have been modified and only pop those (decreasing code size, but increasing compilation time).

今天仍然坚持使用一个return语句的一个原因是易于自动重构。如果您的IDE支持方法提取重构(选择一系列行并将它们转换为一个方法),那么如果您想提取的行中有一个return语句,特别是如果您正在返回一个值,则很难做到这一点。

I've seen it in coding standards for C++ that were a hang-over from C, as if you don't have RAII or other automatic memory management then you have to clean up for each return, which either means cut-and-paste of the clean-up or a goto (logically the same as 'finally' in managed languages), both of which are considered bad form. If your practices are to use smart pointers and collections in C++ or another automatic memory system, then there isn't a strong reason for it, and it become all about readability, and more of a judgement call.

由于错误处理,您已经隐式地拥有多个隐式返回语句,因此要处理它。

但是,就像编程中的典型情况一样,有支持和反对多次返回实践的例子。如果它能让代码更清晰,那就这样做。使用许多控制结构会有所帮助(例如case语句)。