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Globant part 3

 1)ES6 features:

ES6 (ECMAScript 2015) introduced many new features and syntax improvements to JavaScript. Here are some notable ES6 features along with examples:


1. Arrow Functions:

Arrow functions provide a more concise syntax for writing anonymous functions.


javascript

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// ES5

function add(a, b) {

  return a + b;

}


// ES6

const add = (a, b) => a + b;

2. Template Literals:

Template literals allow embedding expressions inside strings using backticks (`).


javascript

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// ES5

var message = "Hello, " + name + "!";


// ES6

let message = `Hello, ${name}!`;

3. Destructuring Assignment:

Destructuring allows extracting values from objects or arrays and assigning them to variables.


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// ES5

var person = { name: 'John', age: 30 };

var name = person.name;

var age = person.age;


// ES6

const { name, age } = { name: 'John', age: 30 };

4. Spread Syntax:

The spread syntax (...) allows expanding iterable objects (e.g., arrays) into individual elements.


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// ES5

var arr1 = [1, 2, 3];

var arr2 = [4, 5, 6];

var combined = arr1.concat(arr2);


// ES6

let arr1 = [1, 2, 3];

let arr2 = [4, 5, 6];

let combined = [...arr1, ...arr2];

5. Default Parameters:

Default parameters allow specifying default values for function parameters.


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// ES5

function greet(name) {

  name = name || 'Guest';

  console.log('Hello, ' + name + '!');

}


// ES6

const greet = (name = 'Guest') => {

  console.log(`Hello, ${name}!`);

};

6. Classes:

ES6 introduced a more convenient syntax for defining classes in JavaScript.


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// ES5

function Person(name, age) {

  this.name = name;

  this.age = age;

}


Person.prototype.greet = function() {

  console.log(`Hello, my name is ${this.name} and I am ${this.age} years old.`);

};


// ES6

class Person {

  constructor(name, age) {

    this.name = name;

    this.age = age;

  }


  greet() {

    console.log(`Hello, my name is ${this.name} and I am ${this.age} years old.`);

  }

}

These are just a few examples of ES6 features. ES6 introduced many more enhancements such as let and const for variable declarations, for...of loops, Promises, and more, which have become standard in modern JavaScript development.


One of the most powerful features introduced in ECMAScript 2015 (ES6) is Promises. Promises provide an elegant and robust solution for managing asynchronous operations, simplifying complex callback structures, and improving code readability.27 Jun 2023



2)Output:

setTimeout(() => {

    console.log("Inside setTimeout callback");

}, 0);


const myPromise = new Promise((resolve, reject) => {

    resolve("Resolved");

});


process.nextTick(() => {

    console.log("Inside process.nextTick callback");

});


myPromise.then((result) => {

    console.log("Promise resolved with:", result);

}).catch((error) => {

    console.error("Promise rejected with:", error);

}).finally(() => {

    console.log("finally");

});

Inside process.nextTick callback
Promise resolved with: Resolved
finally
Inside setTimeout callback
  • process.nextTick() callbacks are executed before any other I/O events or timers, so "Inside process.nextTick callback" is logged first.
  • Promise.then() and Promise.catch() handlers are executed asynchronously after the current execution context is empty. Since the Promise resolves immediately, the .then() handler is invoked next, logging "Promise resolved with: Resolved".
  • The finally() block is executed after the Promise settles, logging "finally".
  • setTimeout() callbacks are executed after a minimum of the specified delay (in this case, 0 milliseconds), but after the current execution context is empty. Therefore, "Inside setTimeout callback" is logged last.




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