返回for循环或外部循环 [英] return in for loop or outside loop

问题描述

今天，有人在Java中使用了 return 关键字。我为循环写了一个简单的来验证某个数组是否在数组中。假设 array 是一个长度为n的数组，这是我的代码：



  for（int i = 0; i< array.length; ++ i）{
 if（array [i] == valueToFind）return true; 
} 
返回false; 
  

现在有人告诉我这不是很好的编程，因为我使用在一个循环内返回语句，这会导致垃圾回收失败。因此，更好的代码将是：



  int i = 0; 
 while（i< array.length&&& array [i]！= valueToFind）++ i; 
返回i！= array.length; 
  

问题是我不能拿出一个适当的补充，为什么第一个for循环isn这是一个很好的做法。有人可以给我一个费用吗？
解决方案
现在有人告诉我，这是不是很好的编程因为我在循环中使用了return语句，这会导致垃圾回收失败。

这是不正确的，并建议您应该以一定的怀疑态度来对待该人的其他建议。

只有一个返回语句（或者更一般地说，只有一个退出点）对于必须自己管理所有资源的语言来说很重要 - 那样的话可以确保你把所有的清理代码放在一个地方。

它在Java中非常有用：只要你知道你应该返回（以及返回值应该），只要返回。这样一来，阅读起来就更简单了 - 你不需要采取其他方法来确定还会发生什么（除了 finally 块）之外， 。

Today someone attended me to bad use of the return keyword in Java. I had written a simple for loop to validate something is in an array. Supposing array is an array of length n this was my code:

for(int i=0; i<array.length; ++i){
    if(array[i]==valueToFind) return true;
}
return false;

Now someone told me that this is not very good programming because I use the return statement inside a loop and this would cause garbage collection to malfunction. Therefore better code would be:

int i = 0;
while(i<array.length && array[i] != valueToFind) ++i;
return i != array.length;

The problem is that I can't come up with a proper explenation of why the first for loop isn't a good practice. Can somebody give me an expenation?

解决方案

Now someone told me that this is not very good programming because I use the return statement inside a loop and this would cause garbage collection to malfunction.

That's incorrect, and suggests you should treat other advice from that person with a degree of skepticism.

The mantra of "only have one return statement" (or more generally, only one exit point) is important in languages where you have to manage all resources yourself - that way you can make sure you put all your cleanup code in one place.

It's much less useful in Java: as soon as you know that you should return (and what the return value should be), just return. That way it's simpler to read - you don't have to take in any of the rest of the method to work out what else is going to happen (other than finally blocks).

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