Java Dinosaur

Tuesday, March 3, 2020

JavaScript - Object

Creating a JavaScript Object

var Employee = {firstName:"John",

lastName:"Doe",

age:50,

eyeColor:"Black",

salary:"60000"};

var Employee = {
  firstName: "John",
  lastName: "Doe",
  age: 50,
  eyeColor: "blue",

salary:"60000"
};

var Employee = new Object();
Employee.firstName = "John";
Employee.lastName = "Doe";
Employee.age = 50;
Employee.eyeColor = "Black";

Employee.salary = "60000";

JavaScript Objects are Mutable

var person = {firstName:"John",

lastName:"Doe",

age:50,

eyeColor:"blue",

salary:"60000"}

var x = person;
x.age = 10; // This will change both x.age and person.age

Javascript - Prototype

<!DOCTYPE html>

<html>

<head>

</head>

<body>

// function constructor

function Employee(name, job, yearOfBirth) {

this.name = name;

this.job = job;

this.yearOfBirth = yearOfBirth;

}

// adding calculateAge() method to the Prototype property

Employee.prototype.calculateAge = function () {

console.log('The current age is: ' + (2019 - this.yearOfBirth));

}

console.log(Employee.prototype);

// creating Object Person1

let Employee1 = new Employee('Elon', 'Astronaut', 1986);

console.log(Person1)

let Employee2 = new Employee('ET', 'Alien', 1997);

console.log(Person2)

Employee1.calculateAge();

Employee2.calculateAge();

</script>

</body>

</html>

Friday, December 6, 2019

Java 0001 : CompletableFuture In Java

We can use CompletableFuture for asynchronous programming which in a non-blocking code. Other than the running main thread, it is used to run a task on a separate thread. Paralleling threads running will avoid the main thread to block or wait the separate thread for task performing until completing. Parallelism thoroughly improve performance of a application.

The most frequently used CompletableFuture methods are:

1. supplyAsync(): It complete its job asynchronously. The result of supplier is run by a task from ForkJoinPool.commonPool() as default. The supplyAsync() method returns CompletableFuture on which we can apply other methods.

2. thenApply(): The method accepts function as an arguments. It returns a new CompletableStage when this stage completes normally. The new stage use as the argument to the supplied function.

3. join(): the method returns the result value when complete. It also throws a CompletionException (unchecked exception) if completed exceptionally.

Example