Difference between revisions of "Java"

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(→‎Basic Level)
(→‎Basic Level)
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#*Create a class ErrorFree with Errors, debug the code and run it
 
#*Create a class ErrorFree with Errors, debug the code and run it
 
#*Eclipse also offers intelligent fixes<br/>  
 
#*Eclipse also offers intelligent fixes<br/>  
−
#:'''Programming features of Eclipse'''
+
#Programming features of Eclipse
 
#*Auto completion
 
#*Auto completion
 
#*Sets the corresponding closing brace when we open the brace
 
#*Sets the corresponding closing brace when we open the brace
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#*Remove semicolon and error details are displayed when mouse is hovered over cross symbol.
 
#*Remove semicolon and error details are displayed when mouse is hovered over cross symbol.
 
#:<br>
 
#:<br>
−
#:'''Fundamental Programming Structures in Java
+
#:'''Fundamental Programming Structures in Java'''
−
#* Numerical datatypes
+
#Numerical datatypes
−
#**Define datatypes and numerical datatypes
+
#*Define datatypes and numerical datatypes
−
#**int
+
#*int
−
#**float
+
#*float
−
#**byte
+
#*byte
−
#**short
+
#*short
−
#**long
+
#*long
−
#**double
+
#*double
−
#**range of each numerical datatypes
+
#*range of each numerical datatypes
−
#**declaration and initializationof numerical datatypes.
+
#*declaration and initializationof numerical datatypes.
−
#**valid and invalid declaration
+
#*valid and invalid declaration
−
#*Arithmetic Operations
+
#Arithmetic Operations
−
#**Define an operator
+
#*Define an operator
−
#**Define arithmetic operators
+
#*Define arithmetic operators
−
#**addition
+
#*addition
−
#**subtraction
+
#*subtraction
−
#**multiplication
+
#*multiplication
−
#**division
+
#*division
−
#**modulo
+
#*modulo
−
#**simple program to demonstrate arithmetic operators
+
#*simple program to demonstrate arithmetic operators
−
#**appropriate datatypes for appropriate values
+
#*appropriate datatypes for appropriate values
−
#**save, compile and run the program<br/>  
+
#*save, compile and run the program<br/>  
−
#* Strings
+
#Strings
−
#**char datatype
+
#*char datatype
−
#**letter, digit, punctuation marks, '''tab''', or a space are all characters.
+
#*letter, digit, punctuation marks, '''tab''', or a space are all characters.
−
#**Program explaining the variable and the character data.
+
#*Program explaining the variable and the character data.
−
#**Introduction to strings
+
#*Introduction to strings
−
#**Creating string by Direct Initialization
+
#*Creating string by Direct Initialization
−
#**Creating string by using new operator
+
#*Creating string by using new operator
−
#**String length()
+
#*String length()
−
#**String concat()
+
#*String concat()
−
#**String toUpperCase()
+
#*String toUpperCase()
−
#**String toLowerCase()<br/>  
+
#*String toLowerCase()<br/>  
−
#*Primitive type conversions
+
#Primitive type conversions
−
#**define type conversion or type casting
+
#*define type conversion or type casting
−
#**higher order integer to lower order integer- Explicit type casting
+
#*higher order integer to lower order integer- Explicit type casting
−
#**program to show explicit type casting
+
#*program to show explicit type casting
−
#**common mistake in explicit type casting.
+
#*common mistake in explicit type casting.
−
#**program to show common mistake in explicit type casting
+
#*program to show common mistake in explicit type casting
−
#**lower order integer to higher order integer – Implicit type casting
+
#*lower order integer to higher order integer – Implicit type casting
−
#**program to show implicit type casting
+
#*program to show implicit type casting
−
#**char to integer
+
#*char to integer
−
#**integer to char
+
#*integer to char
−
#**program to show char to int type casting.
+
#*program to show char to int type casting.
−
# Control flow
+
#:<br>
−
#* Relational Operations
+
#:'''Control flow'''
−
#**boolean datatype
+
#Relational Operations
−
#**equal to and not equal to
+
#*boolean datatype
−
#**less than and less than or equal to
+
#*equal to and not equal to
−
#**greater than and greater than or equal to<br/>  
+
#*less than and less than or equal to
−
#* Logical Operations
+
#*greater than and greater than or equal to<br/>  
−
#**use of logical operators
+
#Logical Operations
−
#**and (&&) operator
+
#*use of logical operators
−
#**example to explain '''and''' operator
+
#*and (&&) operator
−
#**program to demonstrate '''and''' operator
+
#*example to explain '''and''' operator
−
#**or (||) operator
+
#*program to demonstrate '''and''' operator
−
#**example to explain '''or '''operator
+
#*or (||) operator
−
#**program to demonstrate '''or '''operator
+
#*example to explain '''or '''operator
−
#**not (!) operator
+
#*program to demonstrate '''or '''operator
−
#**program to demonstrate '''or '''operator
+
#*not (!) operator
−
#**save, compile and run the programs<br/>  
+
#*program to demonstrate '''or '''operator
−
#*if else construct
+
#*save, compile and run the programs<br/>  
−
#**Conditional Statements and types of Conditional Statements
+
#if else construct
−
#**Use of if statement
+
#*Conditional Statements and types of Conditional Statements
−
#**Syntax for if statement
+
#*Use of if statement
−
#**Program using if statement
+
#*Syntax for if statement
−
#**Use of if else statement
+
#*Program using if statement
−
#**Syntax for if else statement
+
#*Use of if else statement
−
#**Program using if else statement
+
#*Syntax for if else statement
−
#**Use of if else if statement
+
#*Program using if else statement
−
#**Syntax for if else if statement
+
#*Use of if else if statement
−
#**Program using if else if statement<br/>  
+
#*Syntax for if else if statement
−
#* nested if and ternary operator
+
#*Program using if else if statement<br/>  
−
#**explain nested if
+
#nested if and ternary operator
−
#**nested if syntax
+
#*explain nested if
−
#**program to demonstrate nested if
+
#*nested if syntax
−
#**explain the control flow of the program
+
#*program to demonstrate nested if
−
#**explain ternary operator
+
#*explain the control flow of the program
−
#**syntax for ternary operator
+
#*explain ternary operator
−
#**explain the syntax
+
#*syntax for ternary operator
−
#**program to demonstrate ternary operator
+
#*explain the syntax
−
#**comparison between ternary operator and nested if
+
#*program to demonstrate ternary operator
−
#**save, compile and run the program<br/>  
+
#*comparison between ternary operator and nested if
−
#*switch statement
+
#*save, compile and run the program<br/>  
−
#**define switch case statement
+
#switch statement
−
#**compare switch and nested if
+
#*define switch case statement
−
#**switch case syntax
+
#*compare switch and nested if
−
#**working of a switch case statement
+
#*switch case syntax
−
#**use of keyword switch
+
#*working of a switch case statement
−
#**valid and invalid use of keyword '''case'''
+
#*use of keyword switch
−
#**use of keyword default
+
#*valid and invalid use of keyword '''case'''
−
#**use of keyword break
+
#*use of keyword default
−
#**program to demonstrate switch case statement
+
#*use of keyword break
−
#**save, compile and run the program to check the output
+
#*program to demonstrate switch case statement
−
#* while loop
+
#*save, compile and run the program to check the output
−
#**Loop control statement  
+
#while loop
−
#**types of loop control statements
+
#*Loop control statement  
−
#**Introduction to while loop
+
#*types of loop control statements
−
#**syntax of while loop
+
#*Introduction to while loop
−
#**Program using while loop
+
#*syntax of while loop
−
#**Check the output.
+
#*Program using while loop
−
#**Introduction to infinite loop
+
#*Check the output.
−
#**loop variable modification
+
#*Introduction to infinite loop
−
#**Check the output
+
#*loop variable modification
−
#**How to terminate the infinite loop<br/>  
+
#*Check the output
−
#*for loop
+
#*How to terminate the infinite loop<br/>  
−
#**syntax
+
#for loop
−
#**loop continuing condition
+
#*syntax
−
#**loop variable modification<br/>  
+
#*loop continuing condition
−
#*do while loop
+
#*loop variable modification<br/>  
−
#**define do while  
+
#do while loop
−
#**do while syntax
+
#*define do while  
−
#**working of do while loop
+
#*do while syntax
−
#**example of do while loop
+
#*working of do while loop
−
#**explain the do while programming
+
#*example of do while loop
−
#**save, compile and run the program to check the output  
+
#*explain the do while programming
−
#**how different is it from the while loop
+
#*save, compile and run the program to check the output  
−
#**program to demonstrate the differences
+
#*how different is it from the while loop
−
#Arrays  
+
#*program to demonstrate the differences
−
#*Introduction to Arrays
+
#:<br>
−
#**What are arrays
+
#:'''Arrays'''
−
#**Types of arrays
+
#Introduction to Arrays
−
#**How to create arrays
+
#*What are arrays
−
#*Array operations
+
#*Types of arrays
−
#**Accessing array items
+
#*How to create arrays
−
#**Checking for bounds
+
#Array operations
−
#Classes & Objects  
+
#*Accessing array items
 +
#*Checking for bounds
 +
#:<br>
 +
#:'''Classes & Objects''' 
 
#*Creating class  
 
#*Creating class  
−
#**Whatever we can see in this world are all objects
+
#*Whatever we can see in this world are all objects
−
#**Objects can be categorized into groups known as class
+
#*Objects can be categorized into groups known as class
−
#**This is class in real world
+
#*This is class in real world
−
#**Human Being is an example of class in real world
+
#*Human Being is an example of class in real world
−
#**Class in java is the blue print from which individual objects are created
+
#*Class in java is the blue print from which individual objects are created
−
#**Class consists defines a set of properties called variables and a set of behaviors called methods
+
#*Class consists defines a set of properties called variables and a set of behaviors called methods
−
#**Syntax for creating class
+
#*Syntax for creating class
−
#**Create a simple class Student using Eclipse
+
#*Create a simple class Student using Eclipse
−
#**The Student class can contain properties<br/>  
+
#*The Student class can contain properties<br/>  
−
#*Creating Object
+
#Creating Object
−
#**An object is an instance of a class
+
#*An object is an instance of a class
−
#**Each object consist of state and behavior
+
#*Each object consist of state and behavior
−
#**Object stores it state in fields or variables
+
#*Object stores it state in fields or variables
−
#**It exposes its behavior through methods
+
#*It exposes its behavior through methods
−
#**Reference variables
+
#*Reference variables
−
#**Create a class named TestStudent
+
#*Create a class named TestStudent
−
#**Create an object of the Student class
+
#*Create an object of the Student class
−
#**Use new operator
+
#*Use new operator
−
#**Check what the reference variable contains
+
#*Check what the reference variable contains
−
#**Create one more object of the Student class and check what the reference variable contains
+
#*Create one more object of the Student class and check what the reference variable contains
−
#*Instance fields
+
#Instance fields
−
#**Also known as non-static fields
+
#*Also known as non-static fields
−
#**Open the TestStudent class which we have created
+
#*Open the TestStudent class which we have created
−
#**Access the fields roll_number and name using dot operator
+
#*Access the fields roll_number and name using dot operator
−
#**See the output
+
#*See the output
−
#**Initialize the field and see the output
+
#*Initialize the field and see the output
−
#**Change the modifier of the fields to private
+
#*Change the modifier of the fields to private
−
#**Debug the error that you get
+
#*Debug the error that you get
−
#**Change the modifier to protected
+
#*Change the modifier to protected
−
#**Each object of a class will have unique values
+
#*Each object of a class will have unique values
−
#**Create two objects of the Student class  
+
#*Create two objects of the Student class  
−
#*Methods
+
#Methods
−
#**method definition  
+
#*method definition  
−
#**write simple method
+
#*write simple method
−
#**method returning value
+
#*method returning value
−
#**call a method in another method
+
#*call a method in another method
−
#**flow of the program
+
#*flow of the program
−
#**call a static method
+
#*call a static method
−
#**call a method from another class
+
#*call a method from another class
−
#**method signature
+
#*method signature
−
#**method body  
+
#*method body  
−
#Constructors
+
#:<br>
−
#*Default constructor
+
#:'''Constructors'''
−
#**what is a constructor?
+
#Default constructor
−
#**what is a default constructor?
+
#*what is a constructor?
−
#**when is it called?
+
#*what is a default constructor?
−
#**define a constructor
+
#*when is it called?
−
#**initialize the variables
+
#*define a constructor
−
#**call the constructor
+
#*initialize the variables
−
#**difference between constructor and method<br/>  
+
#*call the constructor
−
#*Parameterized constructors
+
#*difference between constructor and method<br/>  
−
#**What is a parameterized constructor?
+
#Parameterized constructors
−
#**create constructor without parameter
+
#*What is a parameterized constructor?
−
#**create a constructor with parameter
+
#*create constructor without parameter
−
#**assign values to the variables in the constructor
+
#*create a constructor with parameter
−
#**pass arguments during the constructor call
+
#*assign values to the variables in the constructor
−
#**working of parameterized constructor
+
#*pass arguments during the constructor call
−
#**show common errors
+
#*working of parameterized constructor
−
#**resolve the errors
+
#*show common errors
−
#**create another parameterized constructor
+
#*resolve the errors
−
#**why to use constructor?
+
#*create another parameterized constructor
−
#*Using this keyword
+
#*why to use constructor?
−
#**this is a reference to the current object
+
#Using this keyword
−
#**helps to avoid name conflicts
+
#*this is a reference to the current object
−
#**we can use this keyword inside a constructor to call another one
+
#*helps to avoid name conflicts
−
#**the constructors must be in the same class
+
#*we can use this keyword inside a constructor to call another one
−
#**explicit constructor invocation
+
#*the constructors must be in the same class
−
#**Explain it using the parameterized constructor code
+
#*explicit constructor invocation
−
#**Make this statement the last one in the constructor
+
#*Explain it using the parameterized constructor code
−
#**You will get an error
+
#*Make this statement the last one in the constructor
−
#**this statement should be the first one inside a constructor
+
#*You will get an error
−
#*Non-static block
+
#*this statement should be the first one inside a constructor
−
#**Non-static block  
+
#Non-static block
−
#**Any code written between two curly brackets  
+
#*Non-static block  
−
#**Executed for each object that is created  
+
#*Any code written between two curly brackets  
−
#**Executes before constructor's execution  
+
#*Executed for each object that is created  
−
#**can initialize instance member variables of the class  
+
#*Executes before constructor's execution  
−
#**create a class named NonStaticTest  
+
#*can initialize instance member variables of the class  
−
#**Create a non-static block and a constructor inside it  
+
#*create a class named NonStaticTest  
−
#**Check the output  
+
#*Create a non-static block and a constructor inside it  
−
#**Include multiple non-static blocks  
+
#*Check the output  
−
#**they will be executed in the sequence in which they appear in the class  
+
#*Include multiple non-static blocks  
−
#**Check the output  
+
#*they will be executed in the sequence in which they appear in the class  
−
#**Non-static block is not a substitute for constructor
+
#*Check the output  
−
#*Constructor Overloading
+
#*Non-static block is not a substitute for constructor
−
#**define multiple constructor
+
#Constructor Overloading
−
#**what is constructor overloading?
+
#*define multiple constructor
−
#**constructor with different number of parameters.
+
#*what is constructor overloading?
−
#**parameters with different datatypes.
+
#*constructor with different number of parameters.
−
#**how is constructor overloaded?
+
#*parameters with different datatypes.
−
#**flow of overloading process.
+
#*how is constructor overloaded?
−
#**advantage of constructor overloading.
+
#*flow of overloading process.
−
#*Method Overloading
+
#*advantage of constructor overloading.
−
#**define multiple methods.
+
#Method Overloading
−
#**methods with same name.
+
#*define multiple methods.
−
#**methods with different number of parameters.
+
#*methods with same name.
−
#**methods with different datatypes of parameter.
+
#*methods with different number of parameters.
−
#**what is method overloading?
+
#*methods with different datatypes of parameter.
−
#**example for overloadin method
+
#*what is method overloading?
−
#**how to overload method?
+
#*example for overloadin method
−
#**advantage of method overloading.
+
#*how to overload method?
−
#**error in method overloading.
+
#*advantage of method overloading.
 +
#*error in method overloading.
  
 
== Intermediate Level ==
 
== Intermediate Level ==
  
 
== Advanced Level ==
 
== Advanced Level ==

Revision as of 11:08, 15 January 2013

Introduction

Welcome to online web tutorials for java
Java[ http://java.sun.com ]is a free and open source high level programming language. It is simple as well as object oriented language. Till date, the Java platform has attracted more than 6.5 million software developers. Java Platform, Standard Edition (Java SE) lets you develop and deploy Java applications on desktops and servers, as well as today's demanding Embedded and Real-Time environments.From laptops to mobile phones, game consoles to scientific supercomputers, music players to the Internet,Set-top boxes to printers, Web cams to medical devices,Ooops that is a huge list to follow,Java is everywhere!!!!!

This set of tutorials will cover features and usage of Java version 1.6.x Please see the associated text box of individual spoken tutorials on the website to decide the versions of Java and OS to which it is applicable.

The Spoken Tutorial Effort for Java is contributed jointly by TalentSprint, Hyderabad and the Spoken Tutorial Team, IIT Bombay. Other contributors who helped in the creation of the scripts are ............

Java Slide Template                                                                                                                               Glossary

Basic Level

Introduction to Java
  1. Getting started with Java – installation
    • Install jdk from Synaptic Package Manager
    • Choose openjdk-6-jdk from the list of packages available
    • Mark it for installation
    • The installation will take a few seconds
    • Verify the installation
    • At the command prompt type java -version, so the version number of the jdk will be displayed
    • Run a simple java program and see if it works
    • Type javac TestProgram.java for compiling the code and java TestProgram for executing the code
  2. Java - First program
    • write simple java program
    • print “My First Java Program!” on Console
    • save the file
    • file name given to the java file
    • compile the file
    • run the file
    • correct the errors
    • naming conventions for class
    • naming conventions for method
    • naming conventions for variable

    Eclipse
  3. Installing Eclipse
    • Install Eclipse on Ubuntu on the Terminal
    • Set up the proxy on the Terminal
    • Then fetch the list of all the available softwares
    • Type sudo apt-get update
    • Then install eclipse on the Terminal
    • Type sudo apt-get install eclipse
    • Verify if Eclipse is installed on the system
    • Installing Eclipse on Debian,Kubuntu,Xubuntu
    • Installing Eclipse on Redhat
    • Installing Eclipse on Fedora,centos and suse linux
  4. Getting started with Eclipse
    • Eclipse is an Integrated Development Environment
    • It is a tool on which one can write, debug and run java programs easily
    • Open Dash Home and type Eclipse in the search box.
    • We get Workspace Launcher
    • On clicking on Workbench we get the Eclipse IDE
    • Go to File->New->Project and select Java Project
    • Create a project named EclipseDemo and create a class inside DemoClass
    • Learn about Package Explorer and Editor portlet
  5. Hello World Program
    • Open Eclipse
    • Create a Java Project named DemoProject
    • Create a class named DemoClass
    • Class name and file name will be the same
    • Eclipse suggests various possibilities as we type a command
    • Eclipse also completes the parentheses by automatically adding the closing parentheses
    • Include the statement that we want to print
    • Eclipse also completes the quotes by adding the closing quote
    • Compile and execute the program
    • Change the code to print
  6. Errors and Debugging
    • When writing a Java Program, here is a list of typical errors:
    • Missing semicolon(;)
    • Missing double quotes(".")
    • Mis-match of filename and classname
    • Typing the print statement n lower case
    • The line which has the error will be indicated with a red cross mark on the left margin
    • The list of errors is displayed by hovering the mouse over the cross mark
    • Create a class ErrorFree with Errors, debug the code and run it
    • Eclipse also offers intelligent fixes
  7. Programming features of Eclipse
    • Auto completion
    • Sets the corresponding closing brace when we open the brace
    • Provides a drop-down list of methods when you start typing the code.
    • Syntax highlighting
    • Classname is highlighted in pink color and method in blue color.
    • Keyboard shortcuts
    • F11 to debug a program and Ctrl plus H to search a specific file.
    • Error highlighting
    • Cross symbol in the program denotes errors
    • Remove semicolon and error details are displayed when mouse is hovered over cross symbol.

    Fundamental Programming Structures in Java
  8. Numerical datatypes
    • Define datatypes and numerical datatypes
    • int
    • float
    • byte
    • short
    • long
    • double
    • range of each numerical datatypes
    • declaration and initializationof numerical datatypes.
    • valid and invalid declaration
  9. Arithmetic Operations
    • Define an operator
    • Define arithmetic operators
    • addition
    • subtraction
    • multiplication
    • division
    • modulo
    • simple program to demonstrate arithmetic operators
    • appropriate datatypes for appropriate values
    • save, compile and run the program
  10. Strings
    • char datatype
    • letter, digit, punctuation marks, tab, or a space are all characters.
    • Program explaining the variable and the character data.
    • Introduction to strings
    • Creating string by Direct Initialization
    • Creating string by using new operator
    • String length()
    • String concat()
    • String toUpperCase()
    • String toLowerCase()
  11. Primitive type conversions
    • define type conversion or type casting
    • higher order integer to lower order integer- Explicit type casting
    • program to show explicit type casting
    • common mistake in explicit type casting.
    • program to show common mistake in explicit type casting
    • lower order integer to higher order integer – Implicit type casting
    • program to show implicit type casting
    • char to integer
    • integer to char
    • program to show char to int type casting.

    Control flow
  12. Relational Operations
    • boolean datatype
    • equal to and not equal to
    • less than and less than or equal to
    • greater than and greater than or equal to
  13. Logical Operations
    • use of logical operators
    • and (&&) operator
    • example to explain and operator
    • program to demonstrate and operator
    • or (||) operator
    • example to explain or operator
    • program to demonstrate or operator
    • not (!) operator
    • program to demonstrate or operator
    • save, compile and run the programs
  14. if else construct
    • Conditional Statements and types of Conditional Statements
    • Use of if statement
    • Syntax for if statement
    • Program using if statement
    • Use of if else statement
    • Syntax for if else statement
    • Program using if else statement
    • Use of if else if statement
    • Syntax for if else if statement
    • Program using if else if statement
  15. nested if and ternary operator
    • explain nested if
    • nested if syntax
    • program to demonstrate nested if
    • explain the control flow of the program
    • explain ternary operator
    • syntax for ternary operator
    • explain the syntax
    • program to demonstrate ternary operator
    • comparison between ternary operator and nested if
    • save, compile and run the program
  16. switch statement
    • define switch case statement
    • compare switch and nested if
    • switch case syntax
    • working of a switch case statement
    • use of keyword switch
    • valid and invalid use of keyword case
    • use of keyword default
    • use of keyword break
    • program to demonstrate switch case statement
    • save, compile and run the program to check the output
  17. while loop
    • Loop control statement
    • types of loop control statements
    • Introduction to while loop
    • syntax of while loop
    • Program using while loop
    • Check the output.
    • Introduction to infinite loop
    • loop variable modification
    • Check the output
    • How to terminate the infinite loop
  18. for loop
    • syntax
    • loop continuing condition
    • loop variable modification
  19. do while loop
    • define do while
    • do while syntax
    • working of do while loop
    • example of do while loop
    • explain the do while programming
    • save, compile and run the program to check the output
    • how different is it from the while loop
    • program to demonstrate the differences

    Arrays
  20. Introduction to Arrays
    • What are arrays
    • Types of arrays
    • How to create arrays
  21. Array operations
    • Accessing array items
    • Checking for bounds

    Classes & Objects
    • Creating class
    • Whatever we can see in this world are all objects
    • Objects can be categorized into groups known as class
    • This is class in real world
    • Human Being is an example of class in real world
    • Class in java is the blue print from which individual objects are created
    • Class consists defines a set of properties called variables and a set of behaviors called methods
    • Syntax for creating class
    • Create a simple class Student using Eclipse
    • The Student class can contain properties
  22. Creating Object
    • An object is an instance of a class
    • Each object consist of state and behavior
    • Object stores it state in fields or variables
    • It exposes its behavior through methods
    • Reference variables
    • Create a class named TestStudent
    • Create an object of the Student class
    • Use new operator
    • Check what the reference variable contains
    • Create one more object of the Student class and check what the reference variable contains
  23. Instance fields
    • Also known as non-static fields
    • Open the TestStudent class which we have created
    • Access the fields roll_number and name using dot operator
    • See the output
    • Initialize the field and see the output
    • Change the modifier of the fields to private
    • Debug the error that you get
    • Change the modifier to protected
    • Each object of a class will have unique values
    • Create two objects of the Student class
  24. Methods
    • method definition
    • write simple method
    • method returning value
    • call a method in another method
    • flow of the program
    • call a static method
    • call a method from another class
    • method signature
    • method body

    Constructors
  25. Default constructor
    • what is a constructor?
    • what is a default constructor?
    • when is it called?
    • define a constructor
    • initialize the variables
    • call the constructor
    • difference between constructor and method
  26. Parameterized constructors
    • What is a parameterized constructor?
    • create constructor without parameter
    • create a constructor with parameter
    • assign values to the variables in the constructor
    • pass arguments during the constructor call
    • working of parameterized constructor
    • show common errors
    • resolve the errors
    • create another parameterized constructor
    • why to use constructor?
  27. Using this keyword
    • this is a reference to the current object
    • helps to avoid name conflicts
    • we can use this keyword inside a constructor to call another one
    • the constructors must be in the same class
    • explicit constructor invocation
    • Explain it using the parameterized constructor code
    • Make this statement the last one in the constructor
    • You will get an error
    • this statement should be the first one inside a constructor
  28. Non-static block
    • Non-static block
    • Any code written between two curly brackets
    • Executed for each object that is created
    • Executes before constructor's execution
    • can initialize instance member variables of the class
    • create a class named NonStaticTest
    • Create a non-static block and a constructor inside it
    • Check the output
    • Include multiple non-static blocks
    • they will be executed in the sequence in which they appear in the class
    • Check the output
    • Non-static block is not a substitute for constructor
  29. Constructor Overloading
    • define multiple constructor
    • what is constructor overloading?
    • constructor with different number of parameters.
    • parameters with different datatypes.
    • how is constructor overloaded?
    • flow of overloading process.
    • advantage of constructor overloading.
  30. Method Overloading
    • define multiple methods.
    • methods with same name.
    • methods with different number of parameters.
    • methods with different datatypes of parameter.
    • what is method overloading?
    • example for overloadin method
    • how to overload method?
    • advantage of method overloading.
    • error in method overloading.

Intermediate Level

Advanced Level

Contributors and Content Editors

Arya Ratish, Minal, Nancyvarkey, PoojaMoolya, Pratham920, Pratik kamble, Priyacst

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