C语言基础复习注意 - 黑马程序员技术交流社区

#include<stdio.h>
void question1(){
//注意少得很么时候用分号; 逗号, 等号= ,什么时候不写
//下面这些,你能保证一个也写不错嘛
char arr[3]={'a','b','c'};
char arr2[3][4] = {
{'a','b','c','d'},
{'a','b','c','d'},
{'a','b','c','d'},
};
char str[]="apple";
char str2[3][10]={
"apple",
"apple",
"apple"
};
struct Person{
char *name;
int age;
float height;
};
struct Person person = {
"jack",
18,
1.78
};
struct Car{
char *name;
int wheel;
float speed;
}car = {"bike",2,34};
enum Season{
kSpring,
kSummer,
kWinter
};
enum Season season = kSpring;
enum Phone{
kApple,
kXioami,
kHuawei
}phone = kApple;
typedef enum IphoneColor{
kWhite,
kBlack,
kRosepink,
kRichgold
}color;
color myphone = kBlack;
}
void question2(){
//野指针
int a=1;
int *p;
*p=a;
printf("*p=%d",*p);
printf("请输入一个整数给*野指针赋值:\n");
scanf("%d",p);
printf("*p=%d",*p);
//使用野指针,编译器不会报错,本来就没有语法错误,但是有"逻辑"错误
}
void question3(){
//用指针定义的字符串
char *name = "jack";
name = "rose";
name = "Django";
*(name+1) = 'h';
printf("%s",name);
//你可以给指针换一串字符串(换个地址),但是不能让这个字符串常量改变
}
void question4(){
//批量赋值的问题
//一.数组的批量赋值
char arr[4];
arr = {1,2,3,4};//错误,数组的批量赋值只能在定义的时候,这样写的话,数组名是个地址,不接收"值"
//二.结构体的批量赋值
struct Person{
char *name;
int age;
}person;
person={"Django",23};//错误
person=(struct Person){"Django",23};//正确,需要一个强转
}
int main()
{
return 0;
}

复制代码