#include "stdio.h"
#include "stdlib.h"

int main(){
    //写入一个整数16
    //32位的int表示为：00000000 00000000 00000000 00010000
    //用unsigned char去模拟
    unsigned char *uc=(unsigned char*)malloc(sizeof(unsigned char)*4); 
    uc[0]=0b00010000;
    uc[1]=0b00000000;
    uc[2]=0b00000000;
    uc[3]=0b00000000;
    printf("%d\n",*((int*)uc));
    //写入一个double
    //32位的float表示 (-1)**S*1.M*2**E
    // 正数 S=0 M=0 E=1 这个数字为2 
    //32 float IEEE编码为 01000000 00000000 00000000 00000000
    uc[0]=0b00000000;
    uc[1]=0b00000000;
    uc[2]=0b00000000;
    uc[3]=0b01000000;
    printf("%f",*((float*)uc));
    return 0;
}

图片说明