Solidity

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Web3.js communicates with the Ethereum Blockchain by using the JSON-RPC method or a Remote Procedure Call protocol.

After learning Solidity, use Web3.js to connect your smart contracts to web pages and build complete dApps.

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Solidity

Solidity

Solidity was proposed in August 2014 by Gavin Wood. The language was then developed by the Ethereum project’s Solidity team, initially led by Christian Reitwiessner. Today Solidity is the most widely used language for smart contracts on Ethereum and other EVM-compatible blockchains.

  • Solidity is an object-oriented, high-level language for implementing smart contracts – programs that govern the behaviour of accounts within the Ethereum state.
  • It is designed to target the Ethereum Virtual Machine (EVM) and is influenced by C++, Python and JavaScript.
  • It is statically typed and supports inheritance, libraries and complex user-defined types.
  • With Solidity you can create contracts for voting, crowdfunding, auctions, lotteries, multi-signature wallets and more.

This Solidity e-learning series helps smart-contract developers build better contracts and applications on Ethereum and EVM-based blockchains. It covers the language step by step – data types, addresses, mappings, bytes, structs, arrays, functions, inheritance, interfaces, events, error handling and payable functions – and then applies it in seven real projects. Every chapter includes notes, a video, resource files, 15 practice questions and a 5-question MCQ test.

Download      E-Notes Start with the Prerequisite
What You Will Learn
Language Basics

Syntax, data types, variables, scope, operators, conditions, loops and strings.

Data Structures

Arrays, enums, mappings and structs – the building blocks of every contract’s state.

Contract Design

Functions, contracts, constructors, inheritance and interfaces.

Events & Errors

Logging with events and safe failure handling with require, revert, assert and custom errors.

Security Patterns

Modifiers, access control, checks-effects-interactions and the withdrawal pattern.

Handling Ether

Payable functions, receive and fallback, and sending Ether safely.

Course Chapters
PREREQUISITE  
Prerequisite : Programming Basics for Solidity

Programming basics before learning Solidity: variables, data types, operators, control flow, functions, OOP and key blockchain ideas for developers.

CHAPTER 1  
Solidity and Remix IDE Setup

What is Solidity, its history and features, how contracts compile to bytecode and ABI, and how to write, compile and deploy your first contract in Remix IDE.

CHAPTER 2  
Solidity Basic Syntax

Solidity basic syntax: SPDX license identifier, pragma version, import, contract structure, comments, NatSpec and naming conventions with examples.

CHAPTER 3  
Solidity Data Types

Solidity data types explained: bool, int, uint, address, address payable, bytes, enum, arrays, string, struct and mapping, with default values and ranges.

CHAPTER 4  
Solidity Variables and Data Locations

Solidity variables: state, local and global variables, constant and immutable, and the storage, memory and calldata data locations with gas tips.

CHAPTER 5  
Scope and Visibility of Variables

Scope of variables in Solidity: public, internal and private state variables, automatic getters, local block scope, and why private data is not secret.

CHAPTER 6
Solidity Operators

Solidity operators: arithmetic with overflow checks, unchecked blocks, assignment, comparison, logical, bitwise, shift and ternary operators with examples.

CHAPTER 7  
Decision Making (if, else if, else)

Decision making in Solidity: if, if-else, else-if chains and the ternary operator, with rules for boolean conditions and a grade calculator example.

CHAPTER 8  
Loops in Solidity

Loops in Solidity: while, do-while and for loops, break and continue, and why unbounded loops are dangerous because of gas limits.

CHAPTER 9  
Strings in Solidity

Strings in Solidity: UTF-8 storage, string vs bytes, memory and calldata, length, comparison with keccak256, string.concat and escape sequences.

CHAPTER 10  
Arrays in Solidity

Solidity arrays: fixed-size and dynamic arrays, storage vs memory arrays, push, pop, length, delete, array slices and out-of-bounds errors.

CHAPTER 11  
Enums in Solidity

Enums in Solidity: declaring user-defined constants, default value, conversion to uint, type(E).min and max, and a state-machine example.

CHAPTER 12  
Mapping in Solidity

Solidity mapping: key-value storage, allowed key and value types, default values, nested mappings, public getters and why mappings cannot be iterated.

CHAPTER 13  
Structs in Solidity

Structs in Solidity: defining custom types, creating struct values, storage and memory references, structs with arrays and mappings, and file-level structs.

CHAPTER 14
Global Variables and Special Functions

Solidity global variables: msg.sender, msg.value, block.timestamp, block.number, block.prevrandao, tx.origin, gasleft and the risks of using them.

CHAPTER 15  
Functions in Solidity

Solidity functions: syntax, parameters and returns, visibility (public, external, internal, private), state mutability (view, pure, payable) and overloading.

CHAPTER 16  
Contracts in Solidity

Solidity contracts: the building block of smart contracts, POP vs OOP vs BOP, contract components, creating contracts with new, and abstract contracts.

CHAPTER 17  
Constructors in Solidity

Solidity constructors: initialising state at deployment, parameters, payable constructors, immutable variables and base constructor arguments.

CHAPTER 18  
Inheritance in Solidity

Inheritance in Solidity: is keyword, virtual and override, super, single, multi-level, hierarchical and multiple inheritance, and linearization order.

CHAPTER 19  
Interfaces in Solidity

Interfaces in Solidity: rules and restrictions, implementing an interface, calling other contracts through an interface, and interfaces vs abstract contracts.

CHAPTER 20  
Events in Solidity

Solidity events: declaring and emitting events, indexed parameters and topics, logs, gas cost and listening to events from a front end with Web3.js.

CHAPTER 21  
Error Handling in Solidity

Solidity error handling: require, revert, assert, custom errors, Error and Panic, try/catch for external calls, and how gas is refunded on revert.

CHAPTER 22  
Function Modifiers in Solidity

Solidity function modifiers: the _; placeholder, modifiers with arguments, onlyOwner, chaining modifiers, execution order and common pitfalls.

CHAPTER 23
Fallback and Receive Functions

Solidity fallback and receive functions: when each one runs, payable rules, the 2300 gas stipend and how a contract receives plain Ether.

CHAPTER 24  
Payable Functions and Sending Ether

Payable functions in Solidity: receiving Ether with msg.value, contract balance, sending Ether with transfer, send and call, and safe withdrawal patterns.

Solidity & Web3.js Projects
PROJECT 1  
Project 1 : Smart Contract for Election System

Solidity project: election voting smart contract with candidates, one vote per address and admin-only results, using struct, enum, mapping and modifiers.

PROJECT 2  
Project 2 : Smart Contract for Lottery System

Solidity project: a lottery smart contract with ticket purchase limits, admin result declaration and keccak256-based winner selection, plus randomness pitfalls.

PROJECT 3  
Project 3 : Smart Contract for Bidding / e-Auction System

Solidity project: an open-bid e-auction smart contract with bidder registration, rising bids, result declaration and payment of the winning bid in Ether.

PROJECT 4  
Project 4 : Smart Contract for Crowdfunding System

Solidity project: a crowdfunding smart contract with fundraiser and donor registration, fund tickets, Ether donations and fund release to the fundraiser.

PROJECT 5  
Project 5 : Smart Contract for Badminton Tournament System

Solidity project: a badminton match smart contract where a referee records points over three rounds and the contract declares the winner on-chain.

PROJECT 6  
Project 6 : Solidity with Web3.js and jQuery Cookies

Solidity and Web3.js project: connect web pages to a smart contract on Ganache, keep the user account in cookies and call contract functions from JavaScript.

PROJECT 7  
Project 7 : EcoRide – A Carpooling dApp

Solidity and Web3.js project: EcoRide carpooling dApp with user registration, ride publishing, search by location, date and vehicle, booking and status updates.

Our Expert

Dr. Vishal Bharvesh

Professional Software Trainer

#Full Stack ERP Developer#Blockchain Developer#Data Scientist & Analyst#System Architect#Software Consultant

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