struct question：NULL终止char *数组

本文介绍了struct question：NULL终止char *数组的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

char * testCharArray [] = { " one"， " two"， " three"， 四， 五， 六， NULL， }; 上面的代码初始化一个NULL终止的char *数组。问题 是为什么括号后需要一个分号（即。};），以及为什么 应该在NULL之后有逗号？ （我在书中看到开始linux 编程第3版。在auther之后附加一个逗号，删除 逗号对代码没有任何作用） $我使用的b $ b编译器是gcc 3.4.4

char *testCharArray[] = { "one", "two", "three", "four", "five", "six", NULL, }; The above code initializes a NULL terminated char* array. The question is why is a semi-colon needed after the bracket (ie. };), and why should there be a comma after NULL ? (I saw in the book beginning linux programming 3rd ed. the auther appended a comma after NULL, removing the comma does nothing to the code) compiler I used was gcc 3.4.4

推荐答案

chy101 ... @ gmail写道： chy101...@gmail wrote: char * testCharArray [] = { " one"， " two"， 三， 四， 五， 六， NULL， }; 上面的代码初始化一个NULL终止的char *数组。问题 是为什么在括号后需要一个分号（即。};） char *testCharArray[] = { "one", "two", "three", "four", "five", "six", NULL, }; The above code initializes a NULL terminated char* array. The question is why is a semi-colon needed after the bracket (ie. };)

因为C中的声明以a结尾分号，结束括号 表示初始化列表的结尾，而不是 声明的结尾。

Because declarations in C end with a semicolon, the closing bracket signifies the end of the initializer list, not the end of the declaration.

和为什么在NULL之后会有逗号？ （我在书中看到开始 linux编程第3版。在auther之后附加一个逗号， 删除逗号对代码没有任何作用） and why should there be a comma after NULL ? (I saw in the book beginning linux programming 3rd ed. the auther appended a comma after NULL, removing the comma does nothing to the code)

初始化列表末尾的尾随逗号是一个功能 旨在帮助自动代码生成器，它们不是必需的。 Robert Gamble

Trailing commas at the end of an initializer list are a feature intended to aid automatic code generators, they are not required. Robert Gamble

Robert Gamble写道： Robert Gamble wrote: chy101 ... @ gmail写道： chy101...@gmail wrote: > char * testCharArray [] = {" one"，" two"，three，four，five，six， NULL，}; >char *testCharArray[] = { "one", "two", "three", "four", "five", "six", NULL,};

.... snip ...

.... snip ...

> > >为什么在NULL之后会有逗号？ （我在书中看到开始linux编程第3版。在auther之后附加一个逗号，删除逗号后对代码不做任何操作） >and why should there be a comma after NULL ? (I saw in the bookbeginning linux programming 3rd ed. the auther appended a commaafter NULL, removing the comma does nothing to the code)

初始化列表末尾的尾随逗号是一个功能 ，旨在帮助自动代码生成器，它们不是必需的。

Trailing commas at the end of an initializer list are a feature intended to aid automatic code generators, they are not required.

IMO更好的方式来编写该声明（并且与所有C版本的b / b兼容）是： char * testCharArray [] = {" one" ，" two" ，"" ，四 ，五 ，六 ，NULL } ; - 一些信息链接： news：news.announce.newusers www.geocities/nnqweb/ www.catb/~esr/faqs/smart-questions .html www.caliburn.nl/ topposting.html http：//wwwmeister .ORG /新闻/ learn2quote .html

IMO a better way to write that declaration (and be compatible with all C versions) is: char *testCharArray[] = { "one" , "two" , "three" , "four" , "five" , "six" , NULL }; -- Some informative links: news:news.announce.newusers www.geocities/nnqweb/ www.catb/~esr/faqs/smart-questions.html www.caliburn.nl/topposting.html wwwmeister/news/learn2quote.html

Robert Gamble写道： Robert Gamble wrote: chy101 ... @ gmail写道： chy101...@gmail wrote: char * testCharArray [] = { " one"， " two"， 三， 四， " five" " six" ;， NULL， }; char *testCharArray[] = { "one", "two", "three", "four", "five", "six", NULL, };

以及为什么在NULL之后会有逗号？ and why should there be a comma after NULL ?

初始化列表末尾的尾随逗号是一个功能 旨在帮助自动代码生成器，它们不是必需的。

Trailing commas at the end of an initializer list are a feature intended to aid automatic code generators, they are not required.

为了更清楚，这个尾随的逗号意味着该程序是 而不是一个结构良好的C90程序 - 虽然这是一个非常普遍的 编译器扩展允许它。

To be clearer, this trailing comma means the program is not a well-formed C90 program -- although it is a very common compiler extension to allow it.