new是个运算符,二malloc是个库函数;
new自动调用类的构造函数,同样,delete自动调用类的析构函数;
new不需要type casting,而malloc需要type casting;
malloc失败返回null,二new失败抛出异常;
http://wiki.answers.com/Q/What_is_difference_between_new_and_malloc
http://wiki.answers.com/Q/What_is_the_difference_between_malloc_and_new_other_than_syntax