Zeek Core Java

Document Chapter Numbers and The Topics Covered in Them

  /* --> Anonymous class is an inner class without a name, which means that     we can declare and instantiate class at the same time.

/* --> get Railway Time(24 hour clock time) --> get 12hour clock time --> get day and date     Use Gregorian Calendar.    */

/*  Gregory calendar is calendar we use in our day to day life.  It has 12 months from January to December  30 or 31 days in each month except February.  In February 28 days(not a leap year) or 29 days when its a leap year   */

  /*  --> Getting Today's Date and Time using Java      --> Methods like  --> getDate(),getDay(),getHours(),getMinutes(),getSeconds(),etc  --> Are depricated in new Java Documentation but in eclipse IDE somehow works  */

  /*  --> Date in java is stored in form of a long number.    --> This long number[currentTimeMillis()] holds the number of milliseconds passed      since 1 January 1970 till now .   */

  /*  Please try using Oracle Documentation for better references.  

  What is hashing in Java and why it is used?

  /* --> An ArrayDeque (also known as an “Array Double Ended Queue”, pronounced as “ArrayDeck”)

  /* Most of the methods of ArrayList and LinkedList are same....

  Difference between ArrayList  and LinkedList

  /* import java.util.*;  ---------> Means you are accessing everything from utils class.

  In this blog I have learned through  various platforms like

                          STARTING ADVANCED JAVA

  /* --> Create an array of index 6.

  /* --> Java finally block is a block used to execute important code such as closing the connection, etc.

  /*  throw and throws is the concept of Exception Handling.  

  /*   (CUSTOM OR USER-DEFINED) EXCEPTIONS  

  /* --> In Java, using a try block inside another try block is permitted. --> It is called as nested try block.

  /* Write a code which deals with specific unchecked exceptions in a unique way. For eg- If Arithmetic Exceptions occurs print an instruction.         If ArrayIndexOutOfBoundsException  occurs print different instruction ,etc */

Types of Java Exceptions

  /*   Sometimes during writing codes.There are some parts that can throw runtime errors.   Because of few runtime errors the entire code crashes(Entire Code cannot run).  

  /*  Explain examples of Syntax,Logical and Runtime errors while coding.   */

  Types of Errors in Java

  /* --> Write a code which gives us the state of the thread(i.e -if thread is new or runnable)   */

/* --> Write a code in which a thread is executed infinitely after 10 seconds of running the code .   */

  /*       Thread Methods:

  /* --> Each thread have a priority. --> Priorities are represented by a number between 1 and 10. ---> In most cases, thread schedular schedules the threads according to their priority      (known as preemptive scheduling).  

/* --> Below are commonly used constructors of Thread class    (Runnable and String defined in Thread class[SEE ORACLE DOCUMENTATION]. Hence use super keyword)  

Life-Cycle of a Thread

  /* --> In Zeek_70_JavaThread we inherited(EXTEND) class Thread for seeing concurrency by threads

/* --> Parallelism- Codes Run simultaneously(At a moment all codes running together).   --> Concurrency - Concurrency means multiple tasks which start, run, and complete in  overlapping time periods,in no specific order(At a moment only one code running).

  What is a thread in Java?

Modifier Class Package Subclass World

  WHAT IS JAVA PACKAGE?

WHAT DOES COMPILER OR INTERPRETER DO ?

  /*  Create a  TV that has features like channelNo(),dishConnection()  Create a LCD_TV that has features of TV plus dolbySound(),hdDisplay(),sleekDesign()  

  /*  --> Create a Monkey class that jumps() and bite() and   -->  An interface of BasicAnimals that eat() and sleep()

  /*Refer to Zeek_49_DynamicDispatch_RuntimePolymorphism

  /*  The following conditions are true regarding inheritance hierarchy:

  /* --->  Create a class MySmartPhone which inherit interfaces MyCamera,MyWifi,MyMemory       and inherits the class CellPhone.

  What is Multiple Inheritance?

  /*  Interface in English is a point where two systems meet and interact.

  /* --> Abstract in English means existing in thought or as an idea without concrete existance.

   /* --> Create a class rectangle with its length and width.  --> Create a class cuboid which is sub class of rectangle(Using concepts of inheritance). --> Use constructors to set its length,width and height. --> Calculate totalSurfaceArea and volume of cuboid    */

    /* --> Create a class circle where you define its radius. --> Create a class cylinder with circle class as parent class (using concepts of inheritance ). --> Use getter setter to set values of radius and height.  */

  /*    Dynamic Method Dispatch or Runtime Polymorphism---

/* ----->Method Overriding- In Java If subclass (child class) has the same method as declared  in the parent class

  /* -----> this is a reference keyword -->  i.e variable name in method and class parameter same then for convenience use  this keyword for reference

  /*    INHERITANCE HIERARCHY-The constructors are executed in order 1 -> 2 -> 3      [1]Parent --> [2]Child --> [3]Grandchild      i.e-This inheritance occurs When you create object of Grandchild class