1. 字符数组和字符指针的大小计算

#include<stdio.h>
#include<string.h>
int main()
{
    char s[15] = "0123456789";
    int a = strlen(s);//10
    int b = sizeof(s);//15
    char *s1 = "0123456789";
    int c = sizeof(s1);//8  64位系统下 指针大小为8
    int d = sizeof(*s1);//1 //*s1指向整个字符串 +1 是整个步长 int 步长4 char步长1
    int e = strlen(s1);//10 //指向字符串首地址 遍历一遍
    //d e 其实就是相当于 数组的首地址  数组的地址 是一致的
     /*a = 0x7ffdc453cbb0
    &a[0] = 0x7ffdc453cbb0
    &a+1 = 0x7ffdc453cbd8
    &a[0]+1 = 0x7ffdc453cbb4
    */
    printf("%d\n",a);
     printf("%d\n",b);
      printf("%d\n",c);
       printf("%d\n",d);
        printf("%d\n",e);
}

2. 短路法则 c=a++ || ++b;

#include<stdio.h>
#include<string.h>
int main()
{
    int a,b,c;
    a=b=4;
    c=a++ || ++b;
    /* 先执行 a++ 4++
        a=4成立 || 短路法则 ++b不执行
        然后a = 5 b = 4 c = 1
    */
    printf("%d\n",a);//5
     printf("%d\n",b);//4
      printf("%d\n",c);//1
}

3. a+b == 0.3 float类型运算

#include<stdio.h>
#include<string.h>
int main()
{
   float a,b;
   a = 0.1;
   b = 0.2;
   if(a+b != 0.3)
   {
       printf("%f\n",a + b);//0.30000
   }

}

4.