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Hello everyone.



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In the last few videos we learned about constructor and this session we will try a few more interesting



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examples



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so this is our class student.



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So the student class has one private property each and then we have our destructor our default constructor



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and then we have to promote based constructor.



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The first one takes a rule number as input and the second parameter is constructor take Agent.



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Rule number as input.



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And then we have a public field a public property rule number and then a public function display good



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data function and stage function.



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OK so now let us create some object



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student S-1 now which constructed data you call it will required default constructor.



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So constructor one called



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so the default constructors construct seven then parameters constructor to which takes on the role number



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is in Porter's constructor to.



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And the constructor which takes a general number is constructor three.



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Okay.



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So in this case constructor one will be called



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Student 2.



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And let us give rule number as input.



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Now which construct page will call it will call the constructor to



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so constructor to called Story entry.



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Now this time I will give a general number.



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So 10 hundred no constructor table be called here



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construct Petrie card



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student for and as 3 as input.



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STUDENT 3 As input now which constructively recoiled.



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So copy construct level recall here



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copy constructor call.



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Now this copy constructors and world copy constructor.



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Okay now what if I do still rent when it goes to rental now which constructively call ahead.



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So no constructor will recall here but assign this to I'd already cleared in the memory.



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So copy assignment operator will be called copy assignment operator.



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Okay copy assignment operator called copy of a large recall here.



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Why.



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Because both S1 and S2 are already created the already existing memory.



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Now let's take one more example.



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Student s 5 equals S3.



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Now which constructor will be called here.



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Copy constructor



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so copy constructor call here.



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Now let's see



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see what is the meaning of the slain we are creating a new object and then we are copying the values



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of S3 into S5 so we can break this line into two lines.



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First we are creating an object and then we are copying the value of student 3 OBJECTION TO STUDENT



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5.



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Okay so in this line default constructor will be called and add this line.



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Copy assignment operator will be called okay.



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Copy assignment operator will be called but if I see Add this line if I see this line then copy constructor



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is being called.



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Why.



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Because what compiler ever do.



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So these are two lines.



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Okay so word compiler Lou would come by level Lou.



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It will optimize it will convert these two lines into one single line compiler will optimize.



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So optimize internally come by level interpreted compiler will interpret this line into one single line



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which is student s 5 as 3 okay.



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So compiler will interpret these two lines in this fashion so if you write student s faith equals S3



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S3 this is same as to render S5 vector S3.



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Okay so that's why copy constructor is called copy construct based.



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Here.



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Okay so this was the special case student that's equals S3.



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This is a special case and you must remember it.



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Okay so this time copy constructor will be called here and not copy assignment operator okay.



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Thank you.