abstract methods in java code example
Example 1: What are abstract methods in java
An abstract method is the method which does’nt have any body.
Abstract method is declared with
keyword abstract and semicolon in place of method body.
public abstract void <method name>();
Ex : public abstract void getDetails();
It is the responsibility of subclass to provide implementation to
abstract method defined in abstract class
Example 2: write a program in which an abstract class is being defined containg an abstract method omputer(int a, int b) and a non abstract method as well
abstract class Sum{
public abstract int compute(int a, int b);
public void disp(){
System.out.println("Method of class Sum");
}
}
class Demo extends Sum{
public int compute(int a, int b){
return a+b;
}
public static void main(String args[]){
Sum obj = new Demo();
System.out.println(obj.compute(3, 7));
obj.disp();
}
}
Example 3: abstract class in java
public abstract class GraphicObject {
abstract void draw();
}
Example 4: how to create an abstract method in java
abstract class Scratch{
abstract public void hello();
abstract String randNum();
}
interface Other{
public void bye();
String randDouble();
}
Example 5: what are abstract classes in java
Sometimes we may come across a situation
where we cannot provide implementation to
all the methods in a class. We want to leave the
implementation to a class that extends it.
In that case we declare a class
as abstract by using abstract keyword on method
signature.In my framework I have created my
PageBase class as super
class of the all page classes.
I have collected all common elements
and functions into PageBase class and
all other page classes extent PageBase class.
By doing so, I don't have to locate very
common WebElements and it provides
reusability in my framework.
i)List<String> webs=driver.getWindowHandles();
=>create a list first to store web URLs in list
ii)findElements evaluates multiple elements so therefore will assigned to List <WebElement>
iii)To handle dynamic elements store it in the list and identify by index:
List<WebElement> all=driver.findElements(By.tagname(“”)); (or other locators).
Also
1)Abstract classes cannot be instantiated
2)An abstarct classes contains abstract method,
concrete methods or both.
3)Any class which extends abstarct class must
override all methods of abstract class
4)An abstarct class can contain either
0 or more abstract method.