add macro

data/3.C语言高阶/4.预处理器/1.宏定义/config.json

@@ -6,5 +6,10 @@
     "C语言"
   ],
   "children": [],
-  "export": []
+  "export": [
+      "define_constant.json",
+      "define_func_1.json",
+      "define_func_2.json",
+      "define_func_3.json"
+  ]
 }
\ No newline at end of file

data/3.C语言高阶/4.预处理器/1.宏定义/define_constant.json

+{
+    "type": "code_options",
+    "author": "幻灰龙",
+    "source": "define_constant.md"
+}
\ No newline at end of file

data/3.C语言高阶/4.预处理器/1.宏定义/define_constant.md

+# 使用宏定义常量
+
+使用宏定义常量定义字符串，输出"Hello,World!"，下面错误的选项是：
+
+## 答案
+
+```c
+#include <stdio.h>
+
+#define HELLO "Hello,"
+#define WORLD "World!"
+#define HELLO_WORLD HELLO##WORLD
+
+int main(int argc, char** args){
+    printf(HELLO_WORLD);
+    return 0;
+}
+```
+
+## 选项
+
+### 直接定义宏字符串常量
+
+```c
+#include <stdio.h>
+
+#define HELLO_WORLD "Hello,World!"
+
+int main(int argc, char** args){
+    printf(HELLO_WORLD);
+    return 0;
+}
+
+```
+
+### 两个字符串常量组合
+
+```c
+#include <stdio.h>
+
+#define HELLO "Hello,"
+#define WORLD "World!"
+
+int main(int argc, char** args){
+    printf(HELLO WORLD);
+    return 0;
+}
+```
+
+### 宏直接拼接
+
+```c
+#include <stdio.h>
+
+#define HELLO "Hello,"
+#define WORLD "World!"
+#define HELLOWORLD HELLO WORLD
+
+int main(int argc, char** args){
+    printf(HELLOWORLD);
+    return 0;
+}
+```
\ No newline at end of file

data/3.C语言高阶/4.预处理器/1.宏定义/define_func3.json

+{
+    "type": "code_options",
+    "author": "幻灰龙",
+    "source": "define_fun_3.md"
+}
\ No newline at end of file

data/3.C语言高阶/4.预处理器/1.宏定义/define_func3.md

+# 使用宏定义函数(3)
+
+当一个宏参数被放进宏体时，这个宏参数会首先被全部展开。定义一个宏，用来打印另外一个宏调用展开后的表达式。例如当调用`printf(MACRO_2_STR( ADD( ADD( 1,000 ), 000 ) ));`时，可以输出展开后的表达式`1+000+000`。
+
+下面哪个选项输出`1+000+000`？
+
+## 答案
+
+```c
+#include <stdio.h>
+
+#define ADD( x, y )  x+y
+#define TO_STR(x) #x
+#define MACRO_2_STR( x ) TO_STR( x )
+
+int main(int argc, char** args){
+    printf(MACRO_2_STR( ADD( ADD( 1,000 ), 000 ) ));
+    return 0;
+}
+```
+
+## 选项
+
+### 选项1
+
+```c
+#include <stdio.h>
+
+#define ADD( x, y )  x+y
+#define MACRO_2_STR( x ) #x
+
+int main(int argc, char** args){
+    printf(MACRO_2_STR( ADD( ADD( 1,000 ), 000 ) ));
+    return 0;
+}
+```
+
+### 选项2
+
+```c
+#include <stdio.h>
+
+#define ADD( x, y )  x+y
+
+int main(int argc, char** args){
+    printf("%d",ADD( ADD(1,1000), 000 ) );
+    return 0;
+}
+```
+
+### 选项3
+
+```c
+#include <stdio.h>
+
+#define CONCAT( x, y )  x##y
+
+int main(int argc, char** args){
+    printf("%d",CONCAT( CONCAT(1, 1000), 000 ) );
+    return 0;
+}
+```
\ No newline at end of file

data/3.C语言高阶/4.预处理器/1.宏定义/define_func_1.json

+{
+    "type": "code_options",
+    "author": "幻灰龙",
+    "source": "define_fun_1.md"
+}
\ No newline at end of file

data/3.C语言高阶/4.预处理器/1.宏定义/define_func_1.md

+# 使用宏定义函数(1)
+
+定义一个宏函数，将符号转成字符串，下面代码正确的选项是？
+
+## 答案
+
+```c
+#include <stdio.h>
+
+#define TO_STR(s) #s
+
+int main(int argc, char** args){
+    printf(TO_STR(1000));
+    printf(TO_STR(HelloWorld!));
+    return 0;
+}
+```
+
+## 选项
+
+### 错误实现
+
+```c
+#include <stdio.h>
+
+#define TO_STR(s) "s"
+
+int main(int argc, char** args){
+    printf(TO_STR(1000));
+    printf(TO_STR(HelloWorld!));
+    return 0;
+}
+```
+
+### 错误调用
+
+```c
+#include <stdio.h>
+
+#define TO_STR(s) #s
+
+int main(int argc, char** args){
+    printf(TO_STR(1000));
+    printf(TO_STR(Hello,World!));
+    return 0;
+}
+```
+
+### 凑巧
+
+```c
+#include <stdio.h>
+
+#define TO_STR(s) ##s
+
+int main(int argc, char** args){
+    printf(TO_STR(1000));
+    printf(TO_STR(HelloWorld!));
+    return 0;
+}
+```
\ No newline at end of file

data/3.C语言高阶/4.预处理器/1.宏定义/define_func_2.json

+{
+    "type": "code_options",
+    "author": "幻灰龙",
+    "source": "define_fun_2.md"
+}
\ No newline at end of file

data/3.C语言高阶/4.预处理器/1.宏定义/define_func_2.md

+# 使用宏定义函数(2)
+
+定义一个拼接符号的宏，例如
+* 使用 `CONCAT(1,000)` 拼接获得`1000`
+* 使用 `CONCAT(1,00)` 拼接获得`100`
+
+下面代码正确的选项是？
+
+## 答案
+
+```c
+
+#include <stdio.h>
+
+#define CONCAT(x,y) x##y
+
+int main(int argc, char** args){
+    printf("%d", CONCAT(1,000));
+    return 0;
+}
+```
+
+## 选项
+
+### 一个井号
+
+```c
+#include <stdio.h>
+
+#define CONCAT(x,y) x#y
+
+int main(int argc, char** args){
+    printf("%d", CONCAT(1,000));
+    return 0;
+}
+```
+
+### 加法
+
+```c
+#include <stdio.h>
+
+#define CONCAT(x,y) x+y
+
+int main(int argc, char** args){
+    printf("%d", CONCAT("1","000"));
+    return 0;
+}
+```
+
+### 凑巧
+
+```c
+#include <stdio.h>
+
+#define CONCAT(x,y) x*1000+y
+
+int main(int argc, char** args){
+    printf("%d", CONCAT(1,000));
+    return 0;
+}
+```
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