b.c: In function ‘main’: b.c:15:2: error: ‘else’ without a previous ‘if’ else ^~~~ 1. 2. 3. 4. 5. 最后我们来使用这个结构再次来改进上面的代码看看效果如何: 1. #include <stdio.h> #define M(n) \ do{\ printf("the n is %d\n",n);\ printf("the M(n) is %d\n"...
编译时直接发生诸如下面的报错信息 In function 'main': :36:2: error: #error "MACRO is not exits" error "MACRO is not exits" ^~~~ 9、#if defined()如果定义了某个宏则编译,不管宏的真假 这个#if defined它不管里面的“x”的逻辑是“真”还是“假”它只管这个程序的前面的宏定义里面有没有定义...
但是如果你的参数超过四个字符,编译器就给给你报错了!error C2015:too many characters in constant :P #x是给x加双引号 char* str = ToString(123132);就成了str="123132"; 如果有#define FUN(a,b) vo##a##b()那么FUN(idma,in)会被替换成void main() 附录: ① 预处理功能: (1)文件包含:可以...
This is a function declaration; it does not provide the body of the function, but it does tell the compiler that it can use this function and expect that it will be defined somewhere. What it Means to Define Something in C and C++ Defining something means providing all of the necessary i...
In above program, X is global symbolic constant, but it is pre-processed before compilation and Y and also global constant whereas Z is local for main function.Macros (#define) can be redefined but const cannotMacro (defined) can be redefined anywhere in the program (by un-defining and ...
// C Program to define the function like macros using// #define#include<stdio.h>// Defining parameterized macros with expression#define CIRCLE_AREA(r) (3.14 * r * r)#define SQUARE_AREA(s) (s * s)intmain(){intradius=21;intside=5;intarea;// Using macros to calculate areas by// pa...
#define M(x,y,z) x*y+z main() int a=1,b=2,c=3; printf("%d\n",M(a+b,b+c,c+a)); A) 19 B) 17 C) 15 D) 12 2以下程序的输出结果是___。 #define M(x,y,z) x*y+z main() int a=1,b=2,c=3; printf("%d\n",M(a+b,b+c,c+ A.); A) 1 3以下程序的...
14 #define MAXBUFF 100 int main() { printf("\nNAME : %s",NAME); printf("\nPI : %f",PI); printf("\nMAXBUFF : %d",MAXBUFF); return 0; } OutputNAME : includhelp.com PI : 3.140000 MAXBUFF : 100 How to define a complex macro with argument (function like macros)?Read: Complex...
从键盘上任意输入圆的半径,显示出圆的周长和面积。请将程序填写完整。 #define PI 3.14 main() { float r,c,s; printf("请输入圆的半径r:"); [填空(1)]; c=2*PI*r; s= [填空(2)]; printf("圆的周长为%f,圆的面积为%f\n",[填空(3)],s); }...
1 宏只是简单的替换,所以M(a+b,b+c,c+a)展开后就是:a+b*b+c+c+a = 122 a是这个数组的首指针,指向数组第一个元素,也就是9,a+5指向数组第6个元素,也就是4.希望你能理解。相关推荐 1#define M(x,y,z) x*y+z main() { int a=1,b=2,c=3; printf("%d",M(a+b,b+c,...