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End this demo let's unhandsome a student example.

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And here is the Student class.

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It is the same class we wrote earlier.

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Only change I made as to public modify our new class declaration reliables constructor and update profile

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method and that's for the sake of this demo site no expose's instance fields with public modifier veen

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are that it is a bad design which leads to tight coupling so let's incorporate the sedation for effective

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.

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Item 14 it does make instances by weight and access them using getters and setters.

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So let's go ahead and make this change.

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So let's make all instance variables private

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just copy this.

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OK so now all the instance fields are by weight.

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Let's also add again an answer for just the name field.

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And it needs to be public.

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That's.

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I'd get her name

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.

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It's out of Sekar

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it's initialized instance really.

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So does not mean equals name.

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So that's the setter on the getter and the instance variables are private.

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Let's also change the constructor.

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So here we have constrictors and the name is getting initialized in this overloaded constructor which

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is it which is being invoked from here.

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So let's just change this.

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So let's just how only one single construct or sort let's make a gender here and let's just remove this

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entire constructor and let's keep it simple

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ones name.

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So we now have a single constructor and we have the update profile Materne here.

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And here is the student class from here.

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If you recall we are actually creating the student objects from here.

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We are creating three student objects initializing their state and printing their names.

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And one of the names has been misspelled as Joanne serviette invoking the dead profiled method here

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and passing the right name.

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And then we are printing the right name after updating the profile.

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And over here we are in the gender field.

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And right now gender field is by red.

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That's what we did.

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So this should not compile.

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Right.

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And even here this constructor we have changed the constructor.

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So we have to pass the right gender.

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So let's let's just do that.

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You just pass me here

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or IGE is male and then what.

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Anita it's female but gender is still a primate and we cannot access it.

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So let's just compile and see.

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So here it says gender has private access.

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And student so we cannot access it directly so we can just remove this.

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In fact we don't have to get a it not how to get her back and we don't need a sitter because we are

51

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sitting here from the concert or Pettit's And so let's just go ahead and delete these three statements

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and also instead of a big profile Let's actually said that mean said the correct name because we added

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a setter and it's just said the correct name.

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So let's just change this to set me.

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And also here we cannot access it so it needs to be get mean.

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So we are calling to get mean.

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So we use only setters and getters no more direct access.

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And hopefully this should compile fine.

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Excellent.

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And it's good on this.

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That's it.

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So we are printing the three students names and then we have the correct name because this was misspelled

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and we are printing the right name here.

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And that's about it.

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So that's information hiding rule.

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And it's also an off Joshua blocks favorite information hiding rule.

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And that's at