![6
01
02
A constructor that have
parameters is known as
parameterized
constructor.
Parameterized
constructor is used to
provide different values to
the distinct objects
Parameterize
dconstructor
Class Rectangle
{
int length; int breadth;
Rectangle(int len, int bre)
{
length=len;
breadth=bre;
}
}
Class demo
{
Public static void main(String args[])
{
Rectangle r1= new Rectangle(20,10);
System.out.println(“length of rectangle=“
r1.length);
System.out.println(“breadth of
rectangle=“ r1.breadth);
}}](https://image.slidesharecdn.com/constructor-200518062942/85/Constructor-in-java-8-320.jpg)
![9
01
02
It is used to create a
temporary object of a
class object.
A copy constructor takes
only one argument, which
is of the type as the class.
Copy
constructor
Class demo
{
Public static void main(String args[])
{
Rectangle r1= new Rectangle(20,10);
Rectangle r2=new Rectangle(r1);
System.out.println(“area of 1st rectangle=“
r1.area());
System.out.println(“area of 2nd rectangle=“
r2.area());
}}](https://image.slidesharecdn.com/constructor-200518062942/85/Constructor-in-java-11-320.jpg)
![10
01
02
A constructor may be
overloaded, so a single
class may have more
than one constructor, all
of which have the same
name but different
argument lists.
Constructor
overloading
Class overloading
{
int x,
float y;
Overloading()
{x=0;y=0.0;}
Overloading(int a)
{x=a; y=0;}
Overloading(int a, float b)
{x=a; y=b;}
Public static void main(String args[])
{
Overloading ov1=new overloading();
Overloading ov2=new overloading(40);
Overloading ov3=new overloading(10,4.5);
}
}](https://image.slidesharecdn.com/constructor-200518062942/85/Constructor-in-java-12-320.jpg)
Ad
More Related Content
What's hot (20)
Similar to Constructor in java (20)
Ad
Recently uploaded (20)
Ad
Constructor in java
- 1. Presented by, Siva Shankari Rajan, CPSV
- 2. CONTENTS What is Constructor Types of Constructor Constructor overloading 1 2 3 4 Passing initial values as arguments
- 3. 1 Java Constructor A constructor in Java is a special method that is used to initialize objects. The constructor is called when an object of a class is created. It can be used to set initial values for object attributes
- 4. 2 Rules for Java Constructor The constructor name must match the name of the class The default constructor is ALWAYS as no-arg constructor Constructors can use any access modifier, including private Constructors must not have a return type.
- 5. 3 Difference Between Constructor and Method Constructor are used to initialize the state of object Constructor must not have return type Constructor compil er provide default constructor . Method is expose the behaviour of object. Method must have return type. Method compiler does't provide. 1 2 3 1 2 3
- 6. 4 Types of Java Constructor Default constructor Parameterized constructor Copy constructor
- 7. 5 01 02 A constructor that have no parameter is known as default constructor. Syntax of default constructor: <class_name>(){} Default Constructor Class Measuring { Private double Metre; Private double kilometer; Private double centimeter; Private double Millimeter; Measuring() { Metre=120; kilometer=10.0; centimeter=12.0; Millimeter=5.0; } Void display() { System.out.println(“kilometer=“+kilometer); } } Output: Kilometer=10.0
- 8. 6 01 02 A constructor that have parameters is known as parameterized constructor. Parameterized constructor is used to provide different values to the distinct objects Parameterize dconstructor Class Rectangle { int length; int breadth; Rectangle(int len, int bre) { length=len; breadth=bre; } } Class demo { Public static void main(String args[]) { Rectangle r1= new Rectangle(20,10); System.out.println(“length of rectangle=“ r1.length); System.out.println(“breadth of rectangle=“ r1.breadth); }}
- 9. 7 01 02 We can create the object with any initial value to extract values in the parameterized constructor Parameterized constructor can pass a value as: 1. An implicit call 2. An explicit call Passing initial values As arguments Implicit call constructor: It retrieves the parameterized constructor even if it is not declared in the main(). We can create the object with any initial value to extract values in the parameterized constructor Explicit call constructor: It helps in creating a temporary instance. A temporary instance remains in the memory as long as it is being used in an expression.
- 10. 8 01 02 It is used to create a temporary object of a class object. A copy constructor takes only one argument, which is of the type as the class. Copy constructor Class Rectangle { int length; int breadth; Rectangle(int len, int bre) { length=len; breadth=bre; } Rectangle(Rectangle obj) { System.out.println(“copy constructor invoked”); length=obj.len; breadth=obj.bre; } int area() { return(length*breadth); }
- 11. 9 01 02 It is used to create a temporary object of a class object. A copy constructor takes only one argument, which is of the type as the class. Copy constructor Class demo { Public static void main(String args[]) { Rectangle r1= new Rectangle(20,10); Rectangle r2=new Rectangle(r1); System.out.println(“area of 1st rectangle=“ r1.area()); System.out.println(“area of 2nd rectangle=“ r2.area()); }}
- 12. 10 01 02 A constructor may be overloaded, so a single class may have more than one constructor, all of which have the same name but different argument lists. Constructor overloading Class overloading { int x, float y; Overloading() {x=0;y=0.0;} Overloading(int a) {x=a; y=0;} Overloading(int a, float b) {x=a; y=b;} Public static void main(String args[]) { Overloading ov1=new overloading(); Overloading ov2=new overloading(40); Overloading ov3=new overloading(10,4.5); } }