Welcome to another installment of the Learn Solidity series. In the last article, we saw how to implement the factory pattern. If you’ve been following from the beginning of this series, then you’ve got the basics down and can start writing your own smart contracts.

Therefore, today I would like to give you the big picture of building decentralized applications and introduce you to web3.js — the missing piece to start building your own dapps.

Before diving into the details of what web3.js …

Welcome to another installment of the Learn Solidity series. In the previous article, we discussed how to create a smart contract from within another smart contract. Today, we will take a look at a typical use case for this scenario.

What Is the Factory Pattern?

The idea of the factory pattern is to have a contract (the factory) that will carry the mission of creating other contracts. The main motivation for this pattern in class-based programming comes from the single-responsibility principle (a class does not need to know how to create instances of other classes), and this pattern provides an abstraction for the constructor.

Welcome to another article in the “Learn Solidity” series. In the last article, we saw how to use functions and applied everything we’ve learned so far to build a multisignature wallet.

In this article, we’ll see how to create a contract from within another contract — and how to define abstract contracts and interfaces.

Contract Creation

Contracts can be created via Ethereum transactions or from within Solidity contracts using the new keyword, which deploys a new instance of that contract and returns its address.

Let’s take a closer look at how this actually works by examining the example given in the Solidity documentation. I made the name variable public so we can examine its value and created an event to be able to read the return value of the createToken function (we’ll have another article for…

Welcome to another article in the Learn Solidity series, in the previous article we concluded with variables, and today I will introduce you to functions and modifiers, which will give you by the end of this article all the pieces to build a multisignature wallet as we will see in the practice section.

Functions in Solidity have the following form :

function function_name(<param_type> <param_name>) <visibility> <state mutability> [returns(<return_type>)]{ ... }

They can be written either outside (free function) or inside a contract.

Return Variables

A function can return an arbitrary number of values as output. …

Welcome to another article in the Learn Solidity series. In the last article, we have seen how data location works and when you can use each of the three locations: memory, storage, and calldata.

In this article, we will continue our journey of learning about variables in Solidity. This time we will focus on reference types, which should explicitly specify the data location, as we mentioned in previous articles. We will also see how you can define mappings, enumerations, and constants.

Arrays

In Solidity we have two types of arrays: storage arrays and memory arrays.

Storage arrays

These arrays are declared as state variables and can have either fixed or dynamic length. …

Welcome to another article in the Learn Solidity series. As I promised in the last article, we will see how data storage works in Solidity.

Ethereum Virtual Machine (EVM)

Before talking about data storage in Solidity, I would like to introduce a few things about the Ethereum virtual machine to make things clearer.

The internal workings of EVM:

Welcome to the second article in the Learn Solidity series. If you haven’t read the first one, I highly recommend that you do in order to set up your development environment and write and deploy your first contract.
In this article, we will have a look at variables in Solidity, their types, how they are stored, and how you can use them.

In Solidity we have two types of variables :

State variables

These variables are declared outside of functions (like the attributes of a class) and are stored permanently in the Ethereum blockchain, more specifically in the storage Merkle Patricia tree, which is part of the information that forms the state of an account (that’s why we call it a state variable). …

Solidity is one of the most popular languages used for developing Ethereum smart contracts, so as someone who wants to be a blockchain developer, I decided to learn how to develop smart contracts using Solidity.

But since I couldn’t find a tutorial with the quality I wanted (one that makes it easy for a beginner to learn the basics in a concise way), I decided to create this series that I hope will introduce you to Solidity programming very quickly and effectively. Enjoy!

Set Up Development Environment

The IDE we will use is Remix. All you need to do is to type this URL. …