It really doesn't matter whether you call them functions or methods because they all represent the same thing: return type name()/(paremeters). In some books they are also called operations, behaviors. In convention, they are called functions in C/C++ and methods in Java.
有些书中有方法之说,那是编书人沿用过去的习惯。
java中没有函数的概念 。 但你可以认为方法就是 函数,只是语法上稍有差别而已