变量的储存类别(Variable storage class)变量的储存类别 C语言 一、静态储存方式与动态储存方式 1、静态储存 a）全局变量全部存储在静态储存区中，在程序开始运行时给全局变量分配存储区，程序执行完毕就释放。 2、动态储存 a）函数形式参数 b）自动变量（未加static声明的局部变量） c）函数调用时...
#include<stdio.h>intmain(){register int i=1;int*p=&i;//error: address of register variable requestedprintf("Value of i: %d\n",*p);} register变量同样没有初始值。另外需要说明的是并不是使用了register变量就一定会比使用automatic变量快,比如你定义了很多的register的变量,导致寄存器的空间不够使用,...
During the first function call, the value ofcis initialized to 1. Its value is increased by 5. Now, the value ofcis 6, which is printed on the screen. During the second function call,cis not initialized to 1 again. It's becausecis a static variable. The valuecis increased by 5. Now...
The "storage class" of a variable determines whether the item has a "global" or "local" lifetime. C calls these two lifetimes "static" and "automatic." An item with a global lifetime exists and has a value throughout the execution of the program. All functions have global lifetimes. ...
Storage class to assign to global_var. storage_class can have one of the following values. Storage ClassDescription 'ExportedGlobal' Defines the variable in the Variable Definitions section of the C file entry_point_name.c. Declares the variable as an extern in the Variable Declarations section ...
Whether the item being declared is a variable or a function Storage-Class Specifiers for External-Level Declarations and Storage-Class Specifiers for Internal-Level Declarations describe the storage-class-specifier terminals in each kind of declaration and explain the default behavior when the storage-cl...
一个在所有函数之外定义的变量具有文件作用域。具有文件作用域的变量其可见性存在于其定义处到文件结尾处。这样的变量也被成为全局变量(global variable)。 intfunction(intarg1,intarg2);intfile_scope =0;intmain(){return0; }intfunction(inta,intb){ ...
(except class members or function parameters). It specifies external linkage, and does not technically affect storage duration, but it cannot be used in a definition of an automatic storage duration object, so allexternobjects have static or thread durations. In addition, a variable declaration ...
Storage class in C Topics Automatic variables External variables Static variables Register variables Scopes and longevity of above types of variables. Few terms Scope: the scope of a variable determines over what part(s) of the program a variable is actually available for use(active). Longevity: ...
If a variable does not have an explicit storage class, it can be assigned an implicit storage class as follows: Variables whose names begin with a letter, dollar sign or underscore that appears in anIMPLICIT STATICstatement have a storage class of static. ...