Overloaded methods are differentiated by the number and the type
of the arguments passed into the method.
重载方法是通过方法参数的数量和类型区分的
You cannot declare more than one method with the same name and
the same number and type of arguments, because the compiler cannot
tell them apart.
如果定义两个函数名称、参数数量、参数类型完全一致(无关返回值),编译器将报错
The compiler does not consider return type when differentiating
methods, so you cannot declare two methods with the same signature
even if they have a different return type.