In Chapter 2, Getting Started with Solidity, and Chapter 3, Control Structures and Contracts, we learned about the Solidity language and its control structures. However, there are a few things that a developer should know while writing smart contracts.

In this chapter, we will look at the best practices of writing smart contracts in Solidity. These best practices will help developers to write bug-free code. Also, there have been many attack patterns that can cause damage to funds present in the smart contracts in production. We will discuss these attacks and how to prevent your contracts from these attacks.

This chapter will cover the following:

• Some of the best practices we should use while writing contracts
• Ethereum on-chain data is public; you should not share any confidential data
• Avoiding untrusted external function calls
• Preventing a front-running attack
• Preventing a reentrancy attack
• Preventing a signature replay attack
• Preventing integer overflow and underflow attacks