As you know, a class provides the blueprint for objects; you create an object from a class.A typical Java program creates many objects, which as you know, interact by invoking methods. Through these object interactions, a program can carry out various tasks, such as implementing a GUI, running an animation, or sending and receiving information over a network. Once an object has completed the work for which it was created, its resources are recycled for use by other objects.
creating a object
In java to create an object has thre parts.They are Declaration,Instantiation,initialization.In Declaration: The code set in bold are all variable declarations that associate a variable name with an object type.In Instantiation: The new keyword is a Java operator that creates the object.In Initialization: The new operator is followed by a call to a constructor, which initializes the new object
Let’s look at syntax of object declaration
classname objectname=new classfunction();
(or)
classname objectname;
objectname=new classfunction();
Example for object declaration
class Areaexp
{
double len;
double brdh;
}
class Areaexp1
{
public static void main(String args[])
{
Areaexp rec=new Areaexp(); //declaring object
double area;
rec.len=6;
rec.brdh=10;
area=rec.len * rec.brdh;
system.out.println("Area is:" +area);
}
}
This would produce the following results
Area is :60
class Areaexp
{
double len;
double brdh;
}
class Areaexp1
{
public static void main(String args[])
{
Areaexp rec=new Areaexp(); //declaring object
double area;
rec.len=6;
rec.brdh=10;
area=rec.len * rec.brdh;
system.out.println("Area is:" +area);
}
}
This would produce the following results
Area is :60
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