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

Understanding the if and if...else decision controls

Solidity provides conditional code execution with the help of the if...else instructions. The general structure of if...else is as follows:

if (this condition/expression is true) {
   Execute the instructions here
} 
else if (this condition/expression is true) {
   Execute the instructions here
} 
else {
   Execute the instructions here
}

if and if...else are keywords in Solidity, and they inform the compiler that they contain a decision control condition – for example, if (a > 10). Here, if contains a condition that can evaluate as either true or false. If a > 10 evaluates to true, then the code instructions that follow in the pair of double-brackets, { and }, should be executed.

else is also a keyword that provides an alternate path if none of the previous conditions are true. It also contains a decision control instruction and executes the code instructions if...