Solidity Functions, Visibility & State Mutability Explained

Description

In this video, we explore Solidity functions, visibility specifiers, and state mutability — essential concepts for writing secure smart contracts. Topics covered: • Function visibility: external, public, internal, and private — when to use each and why it matters for security • State mutability: view (reads state, free to call), pure (no state access, purely computational), and payable (receives ETH) • How external functions are more gas-efficient than public for large calldata • The msg.value global variable and receiving ETH in wei (1 ETH = 10^18 wei) • Why incorrect visibility is a common security vulnerability — making a sensitive function public when it should be internal or private • The difference between transactions (cost gas, modify state) and calls (free, read-only) Code walkthrough of a FunctionExamples contract demonstrating: → increment() — external state-modifying function → getCount() — public view function (free to call externally) → add() — pure computational function → deposit() — payable function that accepts ETH → _helperFunction() — internal helper with underscore naming convention #Solidity #SmartContracts #Blockchain #Ethereum #SolidityFunctions #Web3 #SolidityTutorial #BlockchainDevelopment #Hardhat #LearnSolidity #SolidityVisibility #EthereumDevelopment #Web3Development #SmartContractSecurity #DLT #BlockchainProgramming #SolidityForBeginners #PayableFunction