那么，是什么＆QUOT;返回0＆QUOT;实际上意味着什么呢？ [英] So what does "return 0" actually mean?

问题描述

我是pretty在PHP精通，但我已经开始涉足C.我见过的code

 返回0;
 

在没有返回值的函数结束。这不是在PHP使用的，因为如果一个功能是不具有返回，自动地返回一个NULL值。

所有我问的是，在简单的英语，什么是返回0 实际上做？是像PHP，它返回它的参数作为函数调用的价值？难道只是好的做法呢？

我知道这个问题已经被问过很多次，但我要求它从一个PHP开发人员的点。谷歌抛出了这些问题的答案都没有那么简洁。

解决方案

  

是不是如PHP，它返回它的参数作为的价值
  函数调用？难道只是好的做法呢？

是的，PHP和许多其他语言借用了'C'的收益关键字。而在所有的语言中，收益关键字具有相同的功能 - 从函数返回。随后收益关键字什么是返回给调用者的值。

这是一个好的做法呢？ Yes和No.并非所有功能应返回一个值。而且相当标准库中的少数人甚至，不返回任何值。因此，他们的返回类型是无效。

但主函数返回 0 （也是 EXIT_SUCCESS ），以确定该方案已成功执行。和-1否则（也 EXIT_FAILURE ）

编辑：（感谢@KeithThompson）：

EXIT_FAILURE 是实现定义。 1 是 EXIT_FAILURE 的共同价值，但整点是，你不需要知道。

I'm pretty proficient in PHP, but I've started dabbling with C. I've seen the code

return 0;

at the end of functions that don't return a value. This isn't used in PHP, because if a function is doesn't have a return, a value NULL is automatically returned.

All I'm asking is, in simple English, what does the return 0 actually do? Is it like PHP, where it returns its argument as the value of the function call? Is it just good practice?

I know this question has been asked many times before, but I'm asking it from the point of view of a PHP developer. The answers google throws up haven't been that concise.

解决方案

Is it like php, where it returns its argument as the value of the function call? Is it just good practise?

Yes, PHP and many other languages borrowed the return keyword from 'C'. And in all the languages, the return keyword has the same function - to return from the function. Anything that follows return keyword is the value that is returned to the caller.

Is it a good practise? Yes and No. Not all functions should return a value. And quite a few in the standard library even, do not return any value. Hence their return type is void.

But main function should return 0(also EXIT_SUCCESS) to identify that the program has executed successfully. And -1 otherwise (also EXIT_FAILURE)

EDIT: (Thanks to @KeithThompson):

EXIT_FAILURE is implementation defined. 1 is a common value of EXIT_FAILURE but the whole point is, you need not know.

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