Where to Get Bootstrap 4? Getting started with Bootstrap is quite easy. To begin using Bootstrap with your website you need to get it installed by one of the following techniques: Include bootstrap 4 CDN link in your project from CDN Get it downloaded from getbootstrap.com Bootstrap 4 CDN CDN stands for Content Delivery Network. … Read more
In Java programming, an interface is a collection of method declaration and constant that one or more class can use. It is syntactically similar to the class but the main difference between class and interface is that class contain method declaration with method body and interface method declares without any body. Syntax of interface:
1 2 3 4 5 6 7 8 9 10 11 | access specifier interface InterfaceName { type var1 = value; type var2 = value; ..... .... type method1(parameter list); type method2(parameter list); } |
Final is using for three purpose: final is used to prevent method overriding final is used to prevent inherit a class final is used to make a variable constant final is used to prevent overriding: A method declared as final can’t be overridden.
1 2 3 4 5 6 7 8 9 10 11 | class A { final void show() { } } class B extends A { void show() { //error, can’t override } } |
Because show() declared as final, it can’t be overridden in B. If … Read more
Any class that contains one or more abstract method must also be declared abstract. We can declare an abstract class by using the abstract keyword in front of class keyword at the beginning of the class declaration. An abstract method is a method which declares in super class and defines by the associate subclass. To … Read more
Method overriding is one of the importance concept in Java Programming. What is Method Overriding? In Inheritance hierarchy when a child class defines exact same method that is available in parent class then the method is called overridden method. The process of creating overridden method is called method overriding.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 | class Shape { void draw() { System.out.println("Draw Shape"); } } class Triangle extends Shape { void draw() { System.out.println("Draw Triangle Shape"); } } class Rectangle extends Shape { void draw() { System.out.println("Draw Rectangle Shape"); } } class Circle extends Shape { void draw() { System.out.println("Draw Circle Shape"); } } public class MyClass { public static void main(String args[]) { Shape shape = new Shape(); shape.draw(); Triangle triangle = new Triangle(); triangle.draw(); Rectangle rectangle = new Rectangle(); rectangle.draw(); Circle circle = new Circle(); circle.draw(); } } |
Result
1 2 3 4 | Draw Shape Draw Triangle Shape Draw Rectangle Shape Draw Circle Shape |
We have created … Read more
In java programming it is possible to define a class within another class, such classes are known as nested class. There are two types of nested classes:- 1. Non-static inner class … Read more
There are there types of access modifiers in Java. They are: public private and protected. public: A public data can be accessed by outside of the code in which it is defined. private: A private data can not be accessed by outside of the code in which it is defined. The private data can be … Read more
In Java, there are two ways of argument passing. Call by value Call by reference Call by value Whenever we call a method and passes the value of the variable to the called method, it’s called call by value.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | class Demo { void set(int i, int j) { i = i * 2; j = j / 2; } } public class Test { public static void main(String arg[]) { Demo obj = new Demo(); int a = 15, b = 20; System.out.println("Before call a=" + a + " b=" + b); obj.set(a, b); System.out.println("After call a="+a+" "+" b="+b); } } |
Result
1 2 | Before call a=15 b=20 After call a=15 b=20 |
Note: After multiplication and division value of a and b remain unchanged. … Read more
Local Variable Hides Instance Variable In java when the local variable has the same name as an instance variable, the local variable hides the instance variable.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | public class Test { int a=10, b=10;// instance variable a,b public static void main(String agrs[]) { Test t = new Test(); t.display(); } public void display() { int a = 5;//local variable same name as instance variable System.out.println("Value of local variable a=" + a); System.out.println("Value of instance variable a=" + a + " b=" + b); } } |
Result
1 2 3 | Value of local variable a=5 Value of instance variable a=5 b=10 |
In above program we have two instance variable with value a=10 and b=10. in method display there is a local variable a with value 5. Inside … Read more
A Constructor in a special method that is used to initialize the object. Constructor name should be same as class name. Constructors does not have any return type.
1 2 3 4 5 6 | public class Student(){ //constructor Student(){ } } |
While creating object of above class we use
1 | Student student=new Studet() |
Here new is used to create object and after then the constructor Student() is get called it … Read more
