请高手们看看int 转wchar_t书组的swprintf的问题
double nIn=123;

wchar_t wchar[10]={0};

int len=swprintf(wchar,10,L "%s ",nIn);

cout < <nIn < <endl;
wcout < <wchar < <endl;
//wstring wstr=wchar;

//wcout < <wstr < <endl;
cout < <len < <endl;

请大家看看有什么问题，我的为 wcout < <wchar < <endl;
输出式null,请大家帮帮
谢谢


[解决办法]
double int这个是什么类型啊.
double nIn=123.0;
int len=swprintf(wchar,10,L "%f ",nIn);
cout < <nIn < <endl;
wcout < <wchar < <endl;