3、以下正确的函数定义是( ).A.double fun(int x,int y); {int z; z=x+y; return z；}
3、以下正确的函数定义是().
A.double
fun(int x,int y);
{int z;
z=x+y; return z；}
B.fun(int x,y)
{intz; return z；}
C.double
fun(int x,int y)；
{doublez;
z=x+y;
return z；}
D.doublefun(
x, y)
intx,y;
{doublez; z=x+y; return z；}