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Solidity Programming Essentials

Solidity Programming Essentials

3.6 (10)
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Solidity Programming Essentials

Solidity Programming Essentials

3.6 (10)

Overview of this book

Solidity is a contract-oriented language whose syntax is highly influenced by JavaScript, and is designed to compile code for the Ethereum Virtual Machine. Solidity Programming Essentials will be your guide to understanding Solidity programming to build smart contracts for Ethereum and blockchain from ground-up. We begin with a brief run-through of blockchain, Ethereum, and their most important concepts or components. You will learn how to install all the necessary tools to write, test, and debug Solidity contracts on Ethereum. Then, you will explore the layout of a Solidity source file and work with the different data types. The next set of recipes will help you work with operators, control structures, and data structures while building your smart contracts. We take you through function calls, return types, function modifers, and recipes in object-oriented programming with Solidity. Learn all you can on event logging and exception handling, as well as testing and debugging smart contracts. By the end of this book, you will be able to write, deploy, and test smart contracts in Ethereum. This book will bring forth the essence of writing contracts using Solidity and also help you develop Solidity skills in no time.
Table of Contents (12 chapters)
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The var type variables


One Solidity type that was not discussed in the last chapter is the var data type. var is a special type that can only be declared within a function. There cannot be a state variable in a contract of type var. Variables declared with the var type are known as implicitly typed variable because var does not represent any type explicitly. It informs the compiler that its type is dependent and determined by the value assigned to it the first time. Once a type is determined, it cannot be changed.

Note

The compiler decides the final data type for the var variables instead of a developer mentioning the type. It is therefore quite possible that the type determined by the block.difficulty (uint) current block compiler might not exactly be the type expected by code execution. var cannot be used with the explicit usage of memory location. An explicit memory location needs an explicit variable type.

An example of var is shown in the following screenshot. Variable uintVar8 is of type...

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