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Initialized and declared ‘extern’的warning

Webb4 feb. 2014 · warning: 'extern' variable has an initializer [-Wextern-initializer] This warning is not important, as defining the variable with int counter = 0; still yields a static duration … Webb21 dec. 2010 · extern is declaration mechanism used to tell the compiler that the variable is defined in another file. My Suggestion is that you define a variable in a ".c" file and …

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Webb18 okt. 2024 · Why am I seeing the following warning: warning: ‘i’ initialized and declared ‘extern’. main.c:4:12: warning: ‘i’ initialized and declared ‘extern’ extern int … Webb10 okt. 2015 · 在C语言中,不管是const变量还是非const变量,默认都是extern的,即在别的文件中可用的,只要你在别的文件中用extern声明即可。所以在C语言中定义全局变 … the army\u0027s true colors https://simul-fortes.com

initialized and declared

Webb12 dec. 2024 · warning: 'extern' variable has an initializer [-Wextern-initializer] Basically my system ( Apple LLVM version 8.1.0 (clang-802.0.42)) does not like the explicit initialization with extern keyword. So, you should modify your code as per Ihdina's answer which compiles without error. Webb17 dec. 2024 · 在a.c中进行全局变量的定义:1)exetrn int a = 5; 会跳出警告 ( a.c:3:12: warning: 'a' initialized and declared 'extern' [enabled by default] ),意思是你在头文件中进行了extern的声明,定义的时候已经默认使用extern的初始化和声明,即使用2)种方法进行定义 2)int a = 5; 在b.c文件中使用的时候 (extern int a;)可以不写,程序会在别的 … Webb最佳答案 一旦在 i 函数中定义了一个名为 main 的变量,文件范围内的 i 将被屏蔽并且无法访问 (除非您具有其地址)。 当您以后添加声明 extern int i 时,这与在相同作用域内的名为 i 的局部变量冲突,因为本地人无法进行外部链接。 它确实是 而不是 ,但可以访问全局 i 。 当您删除本地 i 时, extern int i 声明与文件范围内的定义匹配,因此没有错误。 至于 … the gingerbread tea house

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Initialized and declared ‘extern’的warning

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Webbextern int sizeArray = 10; You can't (the compiler is letting you as an extension, but with a warning) initialize a variable at the declaration, only at the definition (there should be a … Webb20 feb. 2024 · 1から自分で作ると全部main.cに書いてしまうので気にもしていなかったが、複数のファイルにまたがる場合のグローバル変数の宣言にはexternをつけるのだそうだ。. 斜めに検索した限りでは、. hoge.h. とかのヘッダファイルを用意して、これに. extern usigned char ...

Initialized and declared ‘extern’的warning

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Webb8 dec. 2004 · extern "Language Name" 则表示是某种语言的变量声明。 所以,这并不是编译器的bug,编译器给出的警告是正确的,因为你在该处对变量进行了初始化,这会强制编译器分配内存并初始化,而这可能会导致错误(因为你可能在别处定义了这个变量)。 而加上大括号以后,只是对编译器的一种欺骗,但是真正错的仍然是你,而非编译器:) … WebbProblem:I received the following warning: 'REGISTER_NAMES' initialized and declared 'extern' [enabled by default] Solution:The GNU Compiler Collection (GCC)4.6.3 …

Webb2 feb. 2024 · 在以下程序中,我认为extern int i;会更改以下i,以参考i在main外部定义的i:. #include extern int i=1; // warning: 'i' initialized and declared 'extern' int … http://wen00072.github.io/blog/2014/12/09/global-variables-from-common-symbol-on-the-c-programming-language/

Webb5 aug. 2024 · I am currently working on implementing a CACC-controller in ROS2 and I would like to use custom messages. However I run into some errors when I try to execute the ros2genmsg command. Webbfile.c:1:12: warning: 'var' initialized and declared 'extern' 因为 extern 的存在通常意味着程序员打算写一个变量声明 (否则你为什么要使用 extern ? ),但初始化器却把它变成 …

Webb结果报 'print' initialized and declared 'extern' 警告,后来把引用和赋值分开写,Warning disappear extern int print; /*引用外部/全局变量*/ print = 2; 记:我是个追求完美的人, …

Webb6 jan. 2024 · You need to declare them as 'extern' in the .h file if you include variables.h in several .cpp files. But then you have to define them in another place - usually in one of … the ginger cat ginWebb12 juni 2009 · extern声明的全局变量的作用范围是整个工程,我们通常在“.h”文件中声明extern变量之后,在其他的“.c”或者“.cpp”中都可以使用。extern扩大了全局变量的作用 … the army values articleWebb15 nov. 2005 · An extern decleration means that a variable is declared and no memory is allocated for it. I've always tought extern means: the variable is declared 'somewhere else' but I want to use it in this file. Not: declared but no memory is allocated. If you try to extern an 'unallocated' variable the compiler the ginger chef