3.20study

#include <stdio.h>

/*
int main()
{
  float f = 5.5;
  //5.5-->101.1  小数点后的二进制转换
  //(-1)^0* 1.011*2^2
  //S=0,M=1.011 E=2-->存储时为2+127=129-->10000001
  //0 10000001 011 00000000000000000000000000
  //0100 0000 1011 0000 0000 0000 0000 0000
  //0x40B00000
  return 0;
}
*/

//整形存储以2进制存储，若以浮点数输出则按照浮点数取出(-1)^s * M * 2^E
//浮点数存储以(-1)^s * M * 2^E，若以整形取出则直接以补码进行换算(正数原反补相同，负数需换算)
int main()
{
  int n = 9;
  //0 00000000 00000000000000000001001 --补码
  
  float* pFloat = (float*)&n;
  printf("n的值为：%d\n", n);//9
  printf("*pFloat的值为：%f\n", *pFloat);//0.000000
  //(-1)^0 0.00000000000000000001001 * 2^-126  -->正无限接近0
  *pFloat = 9.0;
  //1001.0
  //(-1)^0 * 1.001 * 2^3
  //0 10000010 00100000000000000000000

  printf("num的值为：%d\n", n);//n为正数，认为内存中存储的为补码，直接解读
  //1091567616  
  printf("*pFloat的值为：%f\n", *pFloat);//9.000000

  return 0;
}