只接觸了%d、%c、%f等，%lf是什么

#include?<stdio.h>
int?main()
{
????char?c?=?'a';
????int?n?=?c;???//將c賦值給n
????float?f?=?c????;??//將c賦值給f
????double?d?=?c?????;//將c賦值給d
????printf("%d\n",n);
????printf("%f\n",f);
????printf("%lf\n",d);
????return?0;????
}