Solidity Coding Practice

Definition first

What Solidity means

Solidity is a programming language for writing exact instructions, often used for smart contracts Ethereum security and blockchain applications. Start with one mental model: input goes through steps and becomes output.

Minimum run factsFile Contract.solRun solc Contract.solHabit Think about state changes permissions and gas before writing code

Program

An ordered set of instructions. It reads input, follows rules, and produces output.

Value and variable

A value is data. A variable is the name you use to hold and reuse that data.

Function

A named piece of work. It takes input, does one job, and can return a result.

Runtime

Solidity compiler is the place that actually runs code from Contract.sol.

First readable code

Program output

entry point output syntax uint256

uint256 public total = 42;

Output 42

Language lineage

Solidity family tree

See where Solidity comes from, which languages feel close, and what to learn next.

roots

JavaScriptC++Ethereum EVM

currentSoliditySmart contract family

relatives

JavaScript TypeScript Rust

familySmart contract family

best used for

smart contracts, blockchain state, and security sensitive transactions

learn next

JavaScript TypeScript Go

Zero base path

1Read one rule2Predict output3Type from memory4Run checklist5Repeat with one change

Question bank

Search before practice

Pick a stage or search across the open programming bank. Jump straight to the matching drill.

18 matching questions

Search programming questions

Q 1ChoiceStage 1 definitions

Solidity practice 1

Solidity question 1. Choose the statement that matches printing a value.

Q 2ChoiceStage 1 definitions

Solidity practice 2

Solidity question 2. Choose the statement that matches naming a value.

Q 3ChoiceStage 1 definitions

Solidity practice 3

Solidity question 3. Choose the statement that matches reusable function.

Q 4ChoiceStage 1 definitions

Solidity practice 4

Solidity question 4. Choose the statement that matches basic collection.

Q 5ChoiceStage 1 definitions

Solidity practice 5

Solidity question 5. Choose the statement that matches printing a value.

Q 6ChoiceStage 1 definitions

Solidity practice 6

Solidity question 6. Choose the statement that matches naming a value.

Q 7ChoiceStage 1 definitions

Solidity practice 7

Solidity question 7. Choose the statement that matches reusable function.

Q 8ChoiceStage 1 definitions

Solidity practice 8

Solidity question 8. Choose the statement that matches basic collection.

Q 9ChoiceStage 1 definitions

Solidity practice 9

Solidity question 9. Choose the statement that matches printing a value.

Q 10ChoiceStage 1 definitions

Solidity practice 10

Solidity question 10. Choose the statement that matches naming a value.

Q 11ChoiceStage 1 definitions

Solidity practice 11

Solidity question 11. Choose the statement that matches reusable function.

Q 12ChoiceStage 1 definitions

Solidity practice 12

Solidity question 12. Choose the statement that matches basic collection.

Q 13ChoiceStage 1 definitions

Solidity practice 13

Solidity question 13. Choose the statement that matches printing a value.

Q 14ChoiceStage 1 definitions

Solidity practice 14

Solidity question 14. Choose the statement that matches naming a value.

Q 15ChoiceStage 1 definitions

Solidity practice 15

Solidity question 15. Choose the statement that matches reusable function.

Q 16ChoiceStage 1 definitions

Solidity practice 16

Solidity question 16. Choose the statement that matches basic collection.

Q 17ChoiceStage 1 definitions

Solidity practice 17

Solidity question 17. Choose the statement that matches printing a value.

Q 18ChoiceStage 1 definitions

Solidity practice 18

Solidity question 18. Choose the statement that matches naming a value.

Multiple choice

Solidity practice 1

Q 1Choicenew

Question

Solidity question 1. Choose the statement that matches printing a value.

uint256 public total = 42;

Reference

Patterns for Contract.sol

Solidity compilersolc Contract.sol

Recall from memoryRead a small point then write it back without looking

Trace the codeWrite variable values line by line before you run the answer

Type it yourselfCopy less type more and fix one small error at a time

entry point output syntax uint256

Program output

uint256 public total = 42;

Run the smallest file first
Print one known value
Check the output before adding more code

variables assignment types uint256

Values and names

uint256 total = 42;

Give values readable names
Keep one idea per line while learning
Trace the value before changing it

function collection Array

Functions and collections

function add(uint256 a, uint256 b) public pure returns (uint256) {
  return a + b;
}

uint256[] public scores;
scores.push(42);

Keep functions small
Return useful values
Use the common collection before reaching for frameworks

Definition first

What Solidity means

Minimum run factsFile Contract.solRun solc Contract.solHabit Think about state changes permissions and gas before writing code

Program

An ordered set of instructions. It reads input, follows rules, and produces output.

Value and variable

A value is data. A variable is the name you use to hold and reuse that data.

Function

A named piece of work. It takes input, does one job, and can return a result.

Runtime

Solidity compiler is the place that actually runs code from Contract.sol.

First readable code

Program output

entry point output syntax uint256

uint256 public total = 42;

Output 42

Language lineage

Solidity family tree

See where Solidity comes from, which languages feel close, and what to learn next.

roots

JavaScriptC++Ethereum EVM

currentSoliditySmart contract family

relatives

JavaScript TypeScript Rust

familySmart contract family

best used for

smart contracts, blockchain state, and security sensitive transactions

learn next

JavaScript TypeScript Go

Zero base path

1Read one rule2Predict output3Type from memory4Run checklist5Repeat with one change

Question bank

Search before practice

Pick a stage or search across the open programming bank. Jump straight to the matching drill.

18 matching questions

Search programming questions

Q 1ChoiceStage 1 definitions

Solidity practice 1

Solidity question 1. Choose the statement that matches printing a value.

Q 2ChoiceStage 1 definitions

Solidity practice 2

Solidity question 2. Choose the statement that matches naming a value.

Q 3ChoiceStage 1 definitions

Solidity practice 3

Solidity question 3. Choose the statement that matches reusable function.

Q 4ChoiceStage 1 definitions

Solidity practice 4

Solidity question 4. Choose the statement that matches basic collection.

Q 5ChoiceStage 1 definitions

Solidity practice 5

Solidity question 5. Choose the statement that matches printing a value.

Q 6ChoiceStage 1 definitions

Solidity practice 6

Solidity question 6. Choose the statement that matches naming a value.

Q 7ChoiceStage 1 definitions

Solidity practice 7

Solidity question 7. Choose the statement that matches reusable function.

Q 8ChoiceStage 1 definitions

Solidity practice 8

Solidity question 8. Choose the statement that matches basic collection.

Q 9ChoiceStage 1 definitions

Solidity practice 9

Solidity question 9. Choose the statement that matches printing a value.

Q 10ChoiceStage 1 definitions

Solidity practice 10

Solidity question 10. Choose the statement that matches naming a value.

Q 11ChoiceStage 1 definitions

Solidity practice 11

Solidity question 11. Choose the statement that matches reusable function.

Q 12ChoiceStage 1 definitions

Solidity practice 12

Solidity question 12. Choose the statement that matches basic collection.

Q 13ChoiceStage 1 definitions

Solidity practice 13

Solidity question 13. Choose the statement that matches printing a value.

Q 14ChoiceStage 1 definitions

Solidity practice 14

Solidity question 14. Choose the statement that matches naming a value.

Q 15ChoiceStage 1 definitions

Solidity practice 15

Solidity question 15. Choose the statement that matches reusable function.

Q 16ChoiceStage 1 definitions

Solidity practice 16

Solidity question 16. Choose the statement that matches basic collection.

Q 17ChoiceStage 1 definitions

Solidity practice 17

Solidity question 17. Choose the statement that matches printing a value.

Q 18ChoiceStage 1 definitions

Solidity practice 18

Solidity question 18. Choose the statement that matches naming a value.

Multiple choice

Solidity practice 1

Q 1Choicenew

Question

Solidity question 1. Choose the statement that matches printing a value.

uint256 public total = 42;

Reference

Patterns for Contract.sol

Solidity compilersolc Contract.sol

Recall from memoryRead a small point then write it back without looking

Trace the codeWrite variable values line by line before you run the answer

Type it yourselfCopy less type more and fix one small error at a time

entry point output syntax uint256

Program output

uint256 public total = 42;

Run the smallest file first
Print one known value
Check the output before adding more code

variables assignment types uint256

Values and names

uint256 total = 42;

Give values readable names
Keep one idea per line while learning
Trace the value before changing it

function collection Array

Functions and collections

function add(uint256 a, uint256 b) public pure returns (uint256) {
  return a + b;
}

uint256[] public scores;
scores.push(42);

Keep functions small
Return useful values
Use the common collection before reaching for frameworks