Book Image

Solidity Programming Essentials - Second Edition

By : Ritesh Modi
Book Image

Solidity Programming Essentials - Second Edition

By: Ritesh Modi

Overview of this book

Solidity is a high-level language for writing smart contracts, and the syntax has large similarities with JavaScript, thereby making it easier for developers to learn, design, compile, and deploy smart contracts on large blockchain ecosystems including Ethereum and Polygon among others. This book guides you in understanding Solidity programming from scratch. The book starts with step-by-step instructions for the installation of multiple tools and private blockchain, along with foundational concepts such as variables, data types, and programming constructs. You’ll then explore contracts based on an object-oriented paradigm, including the usage of constructors, interfaces, libraries, and abstract contracts. The following chapters help you get to grips with testing and debugging smart contracts. As you advance, you’ll learn about advanced concepts like assembly programming, advanced interfaces, usage of recovery, and error handling using try-catch blocks. You’ll also explore multiple design patterns for smart contracts alongside developing secure smart contracts, as well as gain a solid understanding of writing upgradable smart concepts and data modeling. Finally, you’ll discover how to create your own ERC20 and NFT tokens from scratch. By the end of this book, you will be able to write, deploy, and test smart contracts in Ethereum.
Table of Contents (21 chapters)
1
Part 1: The Fundamentals of Solidity and Ethereum
7
Part 2: Writing Robust Smart Contracts
13
Part 3: Advanced Smart Contracts

Exploring while loops

There are times when we need to execute a code segment repeatedly based on a condition. Solidity provides while loops precisely for this purpose. The general form of the while loop is as follows:

Declare and initialize a counter
while (check the value of counter using an expression or 
  condition) {
    Execute the instructions here
    Increment the value of counter
}

while is a keyword in Solidity, and it informs the compiler that it contains a decision control instruction. If this expression evaluates to true, then the code instructions that follow in the pair of double-brackets ({ and }) should be executed. The while loop keeps executing until the condition turns false.

In the following example, mapping is declared along with counter. This helps loop mapping, since there is no out-of-the-box support in Solidity to do so.

An event is used to get details about transaction information. We will discuss...