Recently, I have access to the Google Developers Scholarship training and part of the tutorials that I find interesting and I thought I should share is cloud computing.

According to Wikipedia cloud computing is defined as the on-demand availability of computer system resources, especially data storage (cloud storage) and computing power, without direct active management by the user. I know that this definition might be a bit complicated to understand but stay with me. First, lets start with the known advantage or benefits of cloud computing; cost, convenience, speed and features. All these benefits are prioritized differently for users; an…


Promising result

JavaScript Promises

Ok, let’s keep it simple, JavaScript Promises is a block of code that runs or promises a result. JavaScript promise object may consist of two kind of codes namely: producing code and consuming code. The producing code is known to run over a period of time before giving desired result, for instance, a page that loads over network while the consuming code on the other hand, waits for the result.

Let us look at a real life scenario, when you walk into a restaurant, you have a waiter who takes your order and promises to return your food within a…


When you tell someone you’d call back later, what does that mean? It means you are taking an action that will require you to take another action later. I hope that makes sense but let me put it this way; while you are on the phone telling them you would call back later, you are already performing an action that calls for another action later. Of course, in the next call you would be saying something different rather than “I’d call back later”.

call back

Javascript callback is a function that passes another function which is executed upon invocation(when it is invoked…


JavaScript class was introduced in ES6, they are known as templates for JavaScript objects (they are not objects but templates) which means they can be used to create multiple objects. In real life practice, there would be a need to create objects of the same kind, whether is for users, goods or details of a certain product in a store and JavaScript class can come in handy at this point as you could write less and more readable codes.

Syntax

class ClassName {
constructor() { … }
}

Breakdown

  • The constructor is a special method that is used to initialize object properties…

I will combine two different topics in todays episode because they are seemingly short.

Hoisting

By default, JavaScript moves declarations to the top of the scope. Would you be surprised to know that you can use variables before even declaring them? This is because JavaScript automatically moves this variable to the top This process is known as Hoisting.

What is Hoisting?

The term hoisting is a behavior in JavaScript that moves a variable or variables to the top of the script. Interestingly, this only works with the var keyword. Let and Const keywords will give reference and syntax error respectively.


A scope is what determines whether or not variables stored can be accessed, in other words it determines the accessibility of a variable. There are two known type of scope namely local scope and global scope.

  • Local Scope: This scope is the one that can only be accessed within a block of enclosed code. For instance, a variable declared in a function or an if else statement can only be accessed in the block of code and any attempt to access the variable outside the block of code will return undefined.
  • Global Scope: This scope can rather be accessed anywhere…

A regular expression is a set of characters that forms a search pattern, these patterns are used to match character combinations in strings. To break it down, regular expression is what is used for text search and text replace operations in JavaScript. There are two expressions that will be globally worked with through out and they include modifiers and patterns.

Regular Expression Modifiers

Modifiers can be used to perform case-insensitive more global searches

  • i: Perform case-insensitive matching
  • g: Perform a global match (find all matches rather than stopping after the first match)
  • m: Perform multiline matching

Regular Expression Patterns

Brackets are used to find a range…


In JavaScript and most of the time, values are being converted to their right type in operations and functions. But sometimes there is a need to explicitly convert a value to the expected type. Frist, let’s talk about data types, I know we are already familiar with this but let us have a recap.

In JavaScript there are 5 different data types that can contain values:

  • string
  • number
  • boolean
  • object
  • function

There are 6 types of objects:

  • Object
  • Date
  • Array
  • String
  • Number
  • Boolean

And 2 data types that cannot contain values:

  • null
  • undefined

The typeof Operator

The typeof operator to find the data…


In JavaScript and most of the time, values are being converted to their right type in operations and functions. But sometimes there is a need to explicitly convert a value to the expected type. Frist, let’s talk about data types, I know we are already familiar with this but let us have a recap.

In JavaScript there are 5 different data types that can contain values:

  • string
  • number
  • boolean
  • object
  • function

There are 6 types of objects:

  • Object
  • Date
  • Array
  • String
  • Number
  • Boolean

And 2 data types that cannot contain values:

  • null
  • undefined

The typeof Operator

The typeof operator to find the data…


Ouch, now what have I done wrong? In programming, there are bound to be errors, we run into bugs and get errors in our console. Now, that is on the programmer’s side, what about the client side? Take for instance, a user is trying to open an account and there has to be a special username because there can only be a username for one user as two users can not have the same and exact username, of course, the user gets an error!!!

There are three major kinds of errors when programming in JavaScript

  • Syntax error
  • Logical error
  • Runtime…

Olajide Blessing Niniola

Front end web developer

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