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Beyond the Basics: A Deep Dive into the Advanced Features of JavaScript

Beyond the Basics: A Deep Dive into the Advanced Features of JavaScript

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pratik lochawala
ยทApr 8, 2023ยท

4 min read

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Table of contents

  • Callback Functions
  • Closures
  • Promises
  • Asynchronous Programming
  • Prototypes
  • Wrapping up!
  • Get in touch ๐Ÿคœ๐Ÿค›

As you become more experienced with JavaScript, you may encounter some advanced topics that can help you create even more powerful and efficient code.

Here are a few Javascript Topics that you must know

  1. Callback Functions

    Callback functions are functions that are passed as arguments to other functions and are executed when the other function completes its task. They can be used to perform asynchronous operations such as loading data from a server or waiting for user input.

    Example:

     function getData(callback) {
       // perform an asynchronous operation to get data
       setTimeout(function() {
         var data = { name: "John", age: 30 };
         callback(data);
       }, 1000);
     }
    
     function displayData(data) {
       console.log(data.name + " is " + data.age + " years old.");
     }
    
     // pass the displayData function as a callback to getData
     getData(displayData);
    

    In this example, getData is a function that performs an asynchronous operation to get data, and it accepts a callback function as an argument. When the asynchronous operation is complete, the getData function calls the callback function with the retrieved data. The displayData function is passed as a callback to getData, and it logs the retrieved data to the console.

  2. Closures

    Closures are functions that have access to variables in their parent function, even after the parent function has returned. They can be used to create private variables and functions that are not accessible from outside the closure.

    Example:

      function createCounter() {
       var count = 0;
    
       function increment() {
         count++;
         console.log(count);
       }
    
       return increment;
     }
    
     var counter = createCounter();
    
     counter(); // logs 1
     counter(); // logs 2
     counter(); // logs 3
    

    In this example, createCounter is a function that returns another function (increment). The increment function has access to the count variable in its parent function (createCounter), even after the parent function has returned. This creates a closure that allows us to create a private counter variable that is not accessible from outside the closure.

  3. Promises

    Promises are objects that represent the eventual completion or failure of an asynchronous operation and allow you to chain multiple asynchronous operations together. They can simplify complex asynchronous code and make it easier to handle errors.

    Example:

     function getData() {
       return new Promise(function(resolve, reject) {
         // perform an asynchronous operation to get data
         setTimeout(function() {
           var data = { name: "John", age: 30 };
           resolve(data);
         }, 1000);
       });
     }
    
     getData()
       .then(function(data) {
         console.log(data.name + " is " + data.age + " years old.");
       })
       .catch(function(error) {
         console.log(error);
       });
    

    In this example, getData returns a Promise object that represents the eventual completion or failure of an asynchronous operation to get data. The then method is called on the Promise object to handle the successful completion of the operation, and the catch method is called to handle any errors that may occur.

  4. Asynchronous Programming

    Asynchronous programming allows you to execute code without blocking the main thread of execution. This can improve the performance of your code and prevent the browser from becoming unresponsive

    Example:

     function getData() {
       // perform an asynchronous operation to get data
       return new Promise(function(resolve, reject) {
         setTimeout(function() {
           var data = { name: "John", age: 30 };
           resolve(data);
         }, 1000);
       });
     }
    
     async function displayData() {
       console.log("Loading data...");
       var data = await getData();
       console.log(data.name + " is " + data.age + " years old.");
     }
    
     displayData();
    

    In this example, getData returns a Promise object that represents an asynchronous operation to get data. The async keyword is used to define the displayData function as an asynchronous function that can use the await keyword to wait for the completion of asynchronous operations. When the displayData function is called, it logs a message to the console, waits for the getData function to complete, retrieves the retrieved data, and logs it to the console.

  5. Prototypes

    Prototypes are objects that provide a blueprint for other objects. They can be used to add methods and properties to existing objects or to create new objects with similar functionality.

    Example:

     function Person(name) {
       this.name = name;
     }
    
     Person.prototype.sayHello = function() {
       console.log("Hello, my name is " + this.name);
     }
    
     var john = new Person("John");
     var jane = new Person("Jane");
    
     john.sayHello(); // logs "Hello, my name is
    

    Wrapping up!

    Share this blog with your friends ๐Ÿ‘ฉ๐Ÿผโ€๐Ÿคโ€๐Ÿง‘๐Ÿผ and developers ๐Ÿ‘จโ€๐Ÿ’ป you know and let them know about these

    Your feedback and comments are very important to me. ๐Ÿ’Œ

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