do-while 结构的基本语法是: #define MACRO_NAME(arguments...) do { \ /* macro definition */ \ } while ( (注意while(0)后面没有分号) 这里的 do { ... } while (0) 实际上是一个包含单个语句的循环结构。这个循环结构的主体部分就是宏定义的代码块。使用 do-while 结构是为了确保代码块中的语...
#include<stdio.h>#defineMalloc(n,type)(type*)malloc(n*sizeof(type))intmain(){// int* p = (int*)malloc(5 * sizeof(int));int*prt=Malloc(5,int);return0;} 当我们将5和int传入到Malloc是,那么n就是5,type就是int,也就是有一个参数是类型,宏是可以实现的,但函数可以实现,预处理之后替换...
[root@rockylinux tmp]# cat macro_define.c /** * 宏命定义的注意事项: * 1、带有参数的宏,参数使用时需要写在"()"之中,这样在宏展开时不会改变设计时的运算级别,保证结果正确;* 举例:#define MAX_INT(x,y) (x)>(y)?(x):(y) * 2、多行合并为一行(代码换行):当“宏定义”内容超过一行时...
Likewise, an identifier currently defined asa function-like macroshall not beredefined by another #define preprocessing directive unless the second definitionis a function-like macro definition that has the same number and spelling ofparameters, and the two replacement lists are identical. 问题2:宏的...
A#definewithout atoken-stringremoves occurrences ofidentifierfrom the source file. Theidentifierremains defined and can be tested by using the#if definedand#ifdefdirectives. The second syntax form defines a function-like macro with parameters. This form accepts an optional list of parameters that must...
#define机制包括了一个规定,允许把参数替换到文本中,这种实现通常称为宏(macro)或定义宏(#define macro)。语法: ●name是宏的名字 ●parament-list是一个用逗号隔开的符号表,它们可能会出现在stuff中(类似于参数,没有类型) ●stuff会用parament-list来实现一定的功能 ...
A #define without a token-string removes occurrences of identifier from the source file. The identifier remains defined and can be tested by using the #if defined and #ifdef directives. The second syntax form defines a function-like macro with parameters. This form accepts an optional list of...
下列具有自變數的巨集範例說明 #define語法的第二種形式: C // Macro to define cursor lines#defineCURSOR(top, bottom) (((top) << 8) | (bottom))// Macro to get a random integer with a specified range#definegetrandom(min, max) \ ((rand()%(int)(((max) + 1)-(min)))+ (min)) ...
59: Macro argument syntax error — 宏参数语法错误60: Macro expansion too long — 宏的扩展以后太长61: Mismatched number of parameters in definition — 定义中参数个数不匹配62: Misplaced break — 此处不应出现break语句63: Misplaced continue — 此处不应出现continue语句64: Misplaced decimal point —...
#define SET(PIN,N) (PIN |= (1<<N)) #define CLR(PIN,N) (PIN &= ~(1<<N)) Here, SET and CLR are the Macro names PIN is the value whose bit to set or/and clear N is the bit number to set or/and clearExample#include <stdio.h> #define SET(PIN,N) (PIN |= (1<<N))...