Avantages of Object Oriented Programming Languages (OOPL)

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The Object Oriented Programming Languages directly represent the real life objects like Car, Jeep, Account,

Customer etc. The features of the OO programming languages like polymorphism, inheritance and

enapsulation make it powerful. [Tip: remember pie which, stands for Polymorphism, Inheritance and

Encapsulation are the 3 pillars of OOPL]

You can determine all the keys in a Map in the following way

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By getting a Set object from the Map and iterating through it

The order of access modifiers from least restrictive to most restrictive

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public, protected, default, private

What is UNICODE?

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Unicode is used for internal representation of characters and strings and it uses 16 bits to represent each other.

What is the difference between constructor and method?

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Constructor will be automatically invoked when an object is created whereas method has to be called explicitly.

What is an Object and how do you allocate memory to it?

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Object is an instance of a class and it is a software unit that combines a structured set of data with a set of operations for inspecting and manipulating that data. When an object is created using new operator, memory is allocated to it.

What are native operating system threads?

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Native operating system threads are those provided by the computer operating system that plays host to a Java application, be it Windows, Mac or GNU/Linux. Operating system threads enable computers to run many programs simultaneously on the same central processing unit (CPU) without clashing over the use of system resources or spending lots of time running one program at the expense of another. Operating system thread management is usually optimised to specific microprocessor architecture and features so that it operates much faster than Java green thread processing.