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What is a constructor in Java or OOP?
- Thread starter Namsu55
- Start date
sedj
Programmer
- Aug 6, 2002
- 5,610
When you instantiate a new object, a specific constructor is called once and only once, for each instantiation of said class.
You should only use a constructor to initialise (typically) private member variables that are relied upon by methods contained within that object.
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You should only use a constructor to initialise (typically) private member variables that are relied upon by methods contained within that object.
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Think of it like buying furniture from IKEA. If they sold you all the pieces for a desk, but they aren't actually assembled into a desk yet, that would be like an object without a constructor. An object with a constructor would be if you buy a fully assembled desk and there's no assembly required on your part. ;-)
Now that's the default constructor (i.e. without passing any arguments). You can also have constructors where you pass some parameters to it so you can customize how you want that object to look.
Now that's the default constructor (i.e. without passing any arguments). You can also have constructors where you pass some parameters to it so you can customize how you want that object to look.
stefanwagner
Programmer
A constructor isn't a method.
It doesn't have a return statement, and you may not call a constructor for an existing Object.
You invoke the constructor by calling 'new' which is another difference to methods.
The constructor creates a new Object, and returns a reference to that object.
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It doesn't have a return statement, and you may not call a constructor for an existing Object.
You invoke the constructor by calling 'new' which is another difference to methods.
The constructor creates a new Object, and returns a reference to that object.
don't visit my homepage:
Or put another way, a constructor is an operator (in the mathematical sense) whose domain is a class (which is abstract in the mathematical sense although in Java, "abstract" means something more particular) and whose range is objects.
_________________
Bob Rashkin
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Bob Rashkin
You can find a lot of links about this:
Cheers,
Dian
Cheers,
Dian
pratham123
Programmer
Constructtor has same name as a calss name with no return statement.
It is called by new operator
It is called by new operator
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