c指针类型的作用

#include <stdio.h>

int main(){
  int i = 123456789;//i的值用16进制表示就是：0x075bcd15
  char *c = (char*)&i;
  printf("char:%d\n", *c);//打印出21，因为是char类型的指针，所以去1个字节，也就是去的是16进制的15，十进制就是21.
  short *s = (short*)&i;
  printf("short:%d\n", *s);//打印出-13035,因为是char类型的指针，所以去2个字节也就是去的是16进制的cd15,十进制就是-13035
  int *pi = &i;
  printf("int:%d\n", *pi);//打印出123456789
}

#include <stdio.h>

int main(){
  int *p = (int*)0x7fffffffe1e4;
  printf("int p=%p, p+1=%p\n", p,p+1);//int p=0x7fffffffe1e4, p+1=0x7fffffffe1e8
  char *c = (char*)p;
  printf("char p=%p, p+1=%p\n", c,c+1);//char p=0x7fffffffe1e4, p+1=0x7fffffffe1e5  
  short *s = (short*)p;
  printf("short p=%p, p+1=%p\n", s,s+1);//short p=0x7fffffffe1e4, p+1=0x7fffffffe1e6
  double *d = (double*)p;
  printf("double p=%p, p+1=%p\n", d,d+1);//double p=0x7fffffffe1e4, p+1=0x7fffffffe1ec
}