new operator
In this chapter you will learn:
Get to know new operator
The new operator has this general form:
class-var = new class-name();class-var
is a variable of the class type being created.class-name
is the name of the class that is being instantiated.
The class name followed by parentheses specifies the constructor for the class.
new with value object
using System; /* ja v a 2 s .c o m*/
class MainClass {
public static void Main() {
int i = new int(); // initialize i to zero
Console.WriteLine("The value of i is: " + i);
}
}
The code above generates the following result.
Creating Objects
A class defines a type of object, but it is not an object itself. An object is an instance of a class.
Objects can be created by using the new
keyword followed by the name of the class.
Rectangle object1 = new Rectangle();
object1
is a reference to an
object based on Rectangle
.
object1
refers to the new object but does
not contain the object data itself.
In fact, you can create an object reference without creating an object at all:
Rectangle object2;
A reference can be made to refer to an object, either by creating a new object, or by assigning it to an existing object, such as this:
Rectangle object3 = new Rectangle();
Rectangle object4 = object3;
The code above creates two object references that
both refer to the same object.
Therefore, any changes to the object made through
object3
will be reflected in subsequent
uses of object4
.
Because objects that are based on classes are referred to by reference, classes are known as reference types.
Next chapter...
What you will learn in the next chapter: