【单选题】Which of the following is a valid function header for the getArea function? The function returns a double number and does not have any formal parameters.
【简答题】The valid function definition among the following is( )A. double fun(int x, int y) { z=x+y; return z;} B. fun(int x, y) { int z; return z;} C. fun(x,y) { int x,y; double z;
z=x+y; return z; } D. doubl...