二进制文件的读写？
我怎么将一个double以二进制的方式写入文件，然后怎样以二进制的方式读进来？
方法越多越好，列举代码

[解决办法]
double a;
FILE *fp;
fp=fopen( "a.txt ", "a+ ");
fwrite(a,sizeof(double),1,fp);//写
fread(a,sizeof(double),1,fp);//读
[解决办法]
fwrite(＆a,sizeof(double),1,fp);//写
fread(＆a,sizeof(double),1,fp);//读
fclose(fp);

[解决办法]
double a;
FILE *fp;
fp=fopen( "a.txt ", "wb ");
fwrite(&a,sizeof(double),1,fp);//写

fp=fopen( "a.txt ", "rb ");
fread(&a,sizeof(double),1,fp);//读