Setting variable values in constructor help

Question

Hey

I've got this Abstract class and I want some other class to inherit from it.

  abstract class Tree {

public string name;

private int age;

private int length;

public int length {

get { return length; }

set { length = value; }

}

class Oak: Tree {

public Oak(string name, int age, int lengthInput) {

this.name = name;

this.age = age;

length = lengthInput;

}

The problem is with setting the value of these variables in the Oak class.

this.name = name - doesn't give me errors, because I stated in the Tree class that name is public.

this.age = age - doesn't work, it says Tree.age is inaccessible due to it's protection level.

length = lengthInput - doesn't give me errors.

So If anyone can explain to me what do these things do?

I think I maybe overprotective with my variables. When should I use private keyword? At this point I have marked all private and created get/set declarations.

Thank you

Felipe Ramos · Answer

Manikavelu is correct you will need to change your access modifier to protected or create a property for the private fields. A slight different implementation would be abstract class Tree { public string name; private int age; private int length; protected Tree(string name int age int length) { this.age = age; this.length = length; this.name = name; } public int Age { get { return age; } } public int Length { get { return length; } } } class Oak : Tree { public Oak(string name int age int lengthInput) : base(name age lengthInput) { } } In this particular case you are making sure your abstract class in setting your fields. You can also add the set in both properties and set the fields in the Oak constructor.

Moose Pickard · Answer

Thanks for the info. I was also wondering what do the other assignments do? this.name = name - doesn't give me errors because I stated in the Tree class that name is public. this.age = age - doesn't work it says Tree.age is inaccessible due to it's protection level. length = lengthInput - doesn't give me errors. If the this.name works then where does it write the info into the abstract class? if the length works where does it write the info?

Manikavelu Velayutham · Answer

Since the age variable is private you cant access it in Inherting class. Either you should declare it as Public or Protected. Private means access is provided only within the class.

Setting variable values in constructor, help