1.虽然可以通过typedef定义一种函数类型例如func_type,但是不能用func_type funcs[10]这样去定义函数数组 2.typedef struct得到的struct没有名字,不能在其中定义构造函数 3.使用函数模板func_type定义的函数f不能对其进行赋值,即对于一个已经实现的函数g(既有声明也有定义),f=*g报错 1 2 3 4
但是在C语言中,struct的定义和声明要用typedef。 【例1.3.2】: [cpp] view plain copy print? typedef struct __Person { string name; int age; float height; }Person; //这是Person是结构体的一个别名 Person person; typedef struct __Person { string name; int age; float height; }Per...
classA{typedefunsignedintUINT;UINT valueA;A():valueA(0){}};classB{UINT valueB;//error C2146: syntax error : missing ';' before identifier 'valueB'//error C4430: missing type specifier - int assumed. Note: C++ does not support default-int}; 上面例子在B类中使用UINT会出错,因为UINT只...
printf("%d\n", c); return 0; } 程序的输出结果是: 36,根本原因就在于 #define 只是简单的字符串替换。 2、功能有差异 typedef 用来定义类型的别名,定义与平台无关的数据类型,与 struct 的结合使用等。 #define 不只是可以为类型取别名,还可以定义常量、变量、编译开关等。 3、作用域不同 #define 没有...
C语言中,struct的定义和声明要用typedef。 【例1.3.2】: typedef struct __Person { string name; int age; float height; }Person; //这是Person是结构体的一个别名 Person person; 如果没有typedef就必须用struct Person person;来声明,如: 【例1.3.3】 ...
typedef struct account { account_name name; char password[20]; }; account user1, user2; Through this way we can use typedef with many concepts for portability and for easy understanding. Conclusion In thisC Tutorial– we learned about typedef in C, with the help of syntax and examples....
B is an alias of class A. C<int> c; // Syntax Error, C cannot be recognized as a type...
James C. Foster, Mike Price Explore book Integer Data Types For UNIX operating systems that use the GCC compiler, the sys/types.h header file is often included intprogram source code to enable use of the more compact and portable data type syntax. This syntax consists of the token int or...
Das typedef struct kann das Deklarieren von Variablen vereinfachen und den äquivalenten Code mit vereinfachter Syntax bereitstellen. Dies kann jedoch zu einem unübersichtlicheren globalen Namensraum führen, was bei umfangreicheren Programmen zu Problemen führen kann. Lassen Sie uns einen Beis...
We can also combine a structure definition with a typedef. Let us see the syntax, typedef struct sStudentsInformations { char acName[20]; int iAge; int iTotalMarks; }sStudInfo; If we used a typedef with the structure definition, then we can also remove the structure tag. ...