abstract-methods

Why do we need abstract classes in Java? If you're never going to make it into an object, why have it in the first place? How do you use it? Why is it there? I'm wondering the same thing with abstract methods. I find it seems like a similar concept to having a super class with NO subclasses that could ever matter to be made. Scary Wombat An abstract class can be used as a type of template for other classes. The abstract class will hold common functionality for all classes that extend it. For example: Abstract Class Animal All animals move and breathe and reproduce so these can be put into the

I'm reading the code that package time , and then I want to know how the func After(d Duration) <-chan Time works. I found the code follows: func After(d Duration) <-chan Time { return NewTimer(d).C } func NewTimer(d Duration) *Timer { c := make(chan Time, 1) t := &Timer{ C: c, r: runtimeTimer{ when: nano() + int64(d), f: sendTime, arg: c, }, } startTimer(&t.r) return t } So I found the definition of startTimer - it's so weird that function startTimer does not have a function body. func startTimer(*runtimeTimer) I want to know that : Where is the real code of startTimer Why an "abstract method