Difference between revisions of "Java"
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#**nested if syntax | #**nested if syntax | ||
#**program to demonstrate nested if | #**program to demonstrate nested if | ||
| − | * explain the control flow of the program | + | *explain the control flow of the program |
| − | * explain ternary operator | + | *explain ternary operator |
| − | * syntax for ternary operator | + | *syntax for ternary operator |
| − | * explain the syntax | + | *explain the syntax |
| − | * program to demonstrate ternary operator | + | *program to demonstrate ternary operator |
| − | * comparison between ternary operator and nested if | + | *comparison between ternary operator and nested if |
| − | * save, compile and run the program<br/> | + | *save, compile and run the program<br/> |
| − | + | #*switch statement | |
| − | #* switch statement | + | #**define switch case 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 | + | |
| − | * save, compile and run the program to check the output | + | |
| − | + | ||
#* while loop | #* while loop | ||
| − | + | #**Loop control statement | |
| − | * Loop control statement | + | #**types of loop control statements |
| − | * types of loop control statements | + | #**Introduction to while loop |
| − | * Introduction to while loop | + | #**syntax of while loop |
| − | * syntax of while loop | + | #**Program using while loop |
| − | * Program using while loop | + | #**Check the output. |
| − | * Check the output. | + | #**Introduction to infinite loop |
| − | * Introduction to infinite loop | + | #**loop variable modification |
| − | * loop variable modification | + | #**Check the output |
| − | * Check the output | + | #**How to terminate the infinite loop<br/> |
| − | * How to terminate the infinite loop<br/> | + | #*for loop |
| − | + | #**syntax | |
| − | + | #**loop continuing condition | |
| − | #* for loop | + | #**loop variable modification<br/> |
| − | + | #*do while loop | |
| − | * syntax | + | #**define do while |
| − | * loop continuing condition | + | #**do while syntax |
| − | * loop variable modification<br/> | + | #**working of do while loop |
| − | + | #**example of do while loop | |
| − | #* do while loop | + | #**explain the do while programming |
| − | + | #**save, compile and run the program to check the output | |
| − | * define do while | + | #**how different is it from the while loop |
| − | * do while syntax | + | #**program to demonstrate the differences |
| − | * working of do while loop | + | #Arrays |
| − | * example of do while loop | + | #*Introduction to Arrays |
| − | * explain the do while programming | + | #**What are arrays |
| − | * save, compile and run the program to check the output | + | #**Types of arrays |
| − | * how different is it from the while loop | + | #**How to create arrays |
| − | * program to demonstrate the differences | + | |
| − | + | ||
| − | # Arrays | + | |
| − | + | ||
| − | #* Introduction to Arrays | + | |
| − | + | ||
| − | * What are arrays | + | |
| − | * Types of arrays | + | |
| − | * How to create arrays | + | |
| − | + | ||
#*Array operations | #*Array operations | ||
| − | + | #**Accessing array items | |
| − | * Accessing array items | + | #**Checking for bounds |
| − | * Checking for bounds | + | |
| − | + | ||
#Classes & Objects | #Classes & Objects | ||
| − | + | #*Creating class | |
| − | #* Creating class | + | #**Whatever we can see in this world are all objects |
| − | + | #**Objects can be categorized into groups known as class | |
| − | * Whatever we can see in this world are all objects | + | #**This is class in real world |
| − | * Objects can be categorized into groups known as class | + | #**Human Being is an example of class in real world |
| − | * This is class in real world | + | #**Class in java is the blue print from which individual objects are created |
| − | * Human Being is an example of class in real world | + | #**Class consists defines a set of properties called variables and a set of behaviors called methods |
| − | * Class in java is the blue print from which individual objects are created | + | #**Syntax for creating class |
| − | * Class consists defines a set of properties called variables and a set of behaviors called methods | + | #**Create a simple class Student using Eclipse |
| − | * Syntax for creating class | + | #**The Student class can contain properties<br/> |
| − | * Create a simple class Student using Eclipse | + | |
| − | * 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 |
| − | + | #**Also known as non-static fields | |
| − | #* Instance fields | + | #**Open the TestStudent class which we have created |
| − | + | #**Access the fields roll_number and name using dot operator | |
| − | * Also known as non-static fields | + | #**See the output |
| − | * Open the TestStudent class which we have created | + | #**Initialize the field and see the output |
| − | * Access the fields roll_number and name using dot operator | + | #**Change the modifier of the fields to private |
| − | * See the output | + | #**Debug the error that you get |
| − | * Initialize the field and see the output | + | #**Change the modifier to protected |
| − | * Change the modifier of the fields to private | + | #**Each object of a class will have unique values |
| − | * Debug the error that you get | + | #**Create two objects of the Student class |
| − | * Change the modifier to protected | + | #*Methods |
| − | * Each object of a class will have unique values | + | #**method definition |
| − | * Create two objects of the Student class | + | #**write simple method |
| − | + | #**method returning value | |
| − | #* Methods | + | #**call a method in another method |
| − | + | #**flow of the program | |
| − | * method definition | + | #**call a static method |
| − | * write simple method | + | #**call a method from another class |
| − | * method returning value | + | #**method signature |
| − | * call a method in another method | + | #**method body |
| − | * flow of the program | + | #Constructors |
| − | * call a static method | + | |
| − | * call a method from another class | + | |
| − | * method signature | + | |
| − | * method body | + | |
| − | + | ||
| − | # Constructors | + | |
| − | + | ||
#*Default constructor | #*Default constructor | ||
| − | + | #**what is a constructor? | |
| − | * what is a constructor? | + | #**what is a default constructor? |
| − | * what is a default constructor? | + | #**when is it called? |
| − | * when is it called? | + | #**define a constructor |
| − | * define a constructor | + | #**initialize the variables |
| − | * initialize the variables | + | #**call the constructor |
| − | * call the constructor | + | #**difference between constructor and method<br/> |
| − | * difference between constructor and method<br/> | + | |
| − | + | ||
#*Parameterized constructors | #*Parameterized constructors | ||
| − | + | #**What is a parameterized constructor? | |
| − | * What is a parameterized constructor? | + | #**create constructor without parameter |
| − | * create constructor without parameter | + | #**create a constructor with parameter |
| − | * create a constructor with parameter | + | #**assign values to the variables in the constructor |
| − | * assign values to the variables in the constructor | + | #**pass arguments during the constructor call |
| − | * pass arguments during the constructor call | + | #**working of parameterized constructor |
| − | * working of parameterized constructor | + | #**show common errors |
| − | * show common errors | + | #**resolve the errors |
| − | * resolve the errors | + | #**create another parameterized constructor |
| − | * create another parameterized constructor | + | #**why to use constructor? |
| − | * why to use constructor? | + | |
| − | + | ||
#*Using this keyword | #*Using this keyword | ||
| − | + | #**this is a reference to the current object | |
| − | * this is a reference to the current object | + | #**helps to avoid name conflicts |
| − | * helps to avoid name conflicts | + | #**we can use this keyword inside a constructor to call another one |
| − | * we can use this keyword inside a constructor to call another one | + | #**the constructors must be in the same class |
| − | * the constructors must be in the same class | + | #**explicit constructor invocation |
| − | * explicit constructor invocation | + | #**Explain it using the parameterized constructor code |
| − | * Explain it using the parameterized constructor code | + | #**Make this statement the last one in the constructor |
| − | * Make this statement the last one in the constructor | + | #**You will get an error |
| − | * You will get an error | + | #**this statement should be the first one inside a constructor |
| − | * this statement should be the first one inside a constructor | + | |
| − | + | ||
#*Non-static block | #*Non-static block | ||
| − | + | #**Non-static block | |
| − | * Non-static block | + | #**Any code written between two curly brackets |
| − | * Any code written between two curly brackets | + | #**Executed for each object that is created |
| − | * Executed for each object that is created | + | #**Executes before constructor's execution |
| − | * Executes before constructor's execution | + | #**can initialize instance member variables of the class |
| − | * can initialize instance member variables of the class | + | #**create a class named NonStaticTest |
| − | * create a class named NonStaticTest | + | #**Create a non-static block and a constructor inside it |
| − | * Create a non-static block and a constructor inside it | + | #**Check the output |
| − | * Check the output | + | #**Include multiple non-static blocks |
| − | * Include multiple non-static blocks | + | #**they will be executed in the sequence in which they appear in the class |
| − | * they will be executed in the sequence in which they appear in the class | + | #**Check the output |
| − | * Check the output | + | #**Non-static block is not a substitute for constructor |
| − | * Non-static block is not a substitute for constructor | + | |
| − | + | ||
#*Constructor Overloading | #*Constructor Overloading | ||
| − | + | #**define multiple constructor | |
| − | * define multiple constructor | + | #**what is constructor overloading? |
| − | * what is constructor overloading? | + | #**constructor with different number of parameters. |
| − | * constructor with different number of parameters. | + | #**parameters with different datatypes. |
| − | * parameters with different datatypes. | + | #**how is constructor overloaded? |
| − | * how is constructor overloaded? | + | #**flow of overloading process. |
| − | * flow of overloading process. | + | #**advantage of constructor overloading. |
| − | * advantage of constructor overloading. | + | |
| − | + | ||
#*Method Overloading | #*Method Overloading | ||
| − | + | #**define multiple methods. | |
| − | * define multiple methods. | + | #**methods with same name. |
| − | * methods with same name. | + | #**methods with different number of parameters. |
| − | * methods with different number of parameters. | + | #**methods with different datatypes of parameter. |
| − | * methods with different datatypes of parameter. | + | #**what is method overloading? |
| − | * what is method overloading? | + | #**example for overloadin method |
| − | * example for overloadin method | + | #**how to overload method? |
| − | * how to overload method? | + | #**advantage of method overloading. |
| − | * advantage of method overloading. | + | #**error in method overloading. |
| − | * error in method overloading. | + | |
== Intermediate Level == | == Intermediate Level == | ||
== Advanced Level == | == Advanced Level == | ||
Revision as of 18:40, 14 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 ............
Basic Level
- Introduction to Java
- 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
- 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
- Getting started with Java – installation
- Eclipse
- 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
- 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
- Add the println statement in
- 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
- 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
- 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.
- Installing Eclipse
- Fundamental Programming Structures in Java
- 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
- 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
- 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()
- 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.
- Numerical datatypes
- Control flow
- 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
- 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
- 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
- nested if and ternary operator
- explain nested if
- nested if syntax
- program to demonstrate nested if
- Relational Operations
- 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
- 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
- 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
- for loop
- syntax
- loop continuing condition
- loop variable modification
- 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
- switch statement
- Arrays
- Introduction to Arrays
- What are arrays
- Types of arrays
- How to create arrays
- Array operations
- Accessing array items
- Checking for bounds
- Introduction to Arrays
- 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
- 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
- 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
- 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
- Creating class
- Constructors
- 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
- 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?
- 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
- 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
- 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.
- 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.
- Default constructor
Intermediate Level
Advanced Level
Contributors and Content Editors
Arya Ratish, Minal, Nancyvarkey, PoojaMoolya, Pratham920, Pratik kamble, Priyacst
