Day 6 - Data Types - DEV Community

Vedant Chainani · 2022-06-03T13:33:00Z

envoy1084 / 30-Days-of-Solidity 30 Days of Solidity step-by-step guide to learn Smart Contract Development. <img src="https://camo.githubusercontent.com/87b6dc8da97a62c437535fde4090ca5277f0a2f54fc8da0a80b54e01e564dbd7/68747470733a2f2f696d672e736869656c64732e696f2f7374617469632f76313f6c6162656c3d736f6c6964697479266d6573736167653d76302e382e3726636f6c6f723d326561343466266c6f676f3d736f6c6964697479" alt="Solidity" data-canonical-src="https://img.shields.io/static/v1?label=solidity&message=v0.8.7&color=2ea44f&logo=solidity" style="max-width: 100%;"> WARNING : This repository is currently undergoing updates and revisions to incorporate the latest information and advancements in Solidity programming. Please be advised that the content may not be up-to-date or accurate during this time. We expect the updates to be completed within the next 30 days, and appreciate your patience during this process. Thank you for your understanding. Contents Day 1 - Licenses and Pragma Day 2 - Comments Day 3 - Initializing Basic Contract Day 4 - Variables and Scopes Day 5 - Operators Day 6 - Types Day 7 - Functions Day 8 - Loops Day 9 - Decision Making Day 10 - Arrays Day 11 - Array Operations Day 12 - Enums Day 13 - Structs Day 14 - Mappings Day 15 - Units Day 16 - Require Statement Day 17 - Assert Statement Day 18 - Revert Statement Day 19 - Function Modifiers Day 20 … View on GitHub This is Day 6 of 30 in Solidity Series Today I Learned About Data Types in Solidity. Data Types Solidity offers the programmer a rich assortment of built-in as well as user defined data types. Following table lists down seven basic C++ data types − Type Keyword Values Boolean bool true/false Integer int/uint Signed and unsigned integers of varying sizes. Integer int8 to int256 Signed int from 8 bits to 256 bits. int256 is the same as int. Integer uint8 to uint256 Unsigned int from 8 bits to 256 bits. uint256 is the same as uint. Fixed Point Numbers fixed/ufixed Signed and unsigned fixed point numbers of varying sizes. Fixed Point Numbers fixedMxN Signed fixed point number where M represents number of bits taken by type and N represents the decimal points. M should be divisible by 8 and goes from 8 to 256. N can be from 0 to 80. fixed is same as fixed128x18. Hexadecimal address Holds a 20 byte value (size of an Ethereum address). example - // SPDX-License-Identifier: MIT pragma solidity ^0.8.7; contract MyTypes { bool myBool = true; // if bool value is not specified then it is false by default // Unsigned Integers - can only take 0 or positive values range = 0 - (2^n - 1) uint8 myUint8 = 84; // 0 - 255 uint16 myUint16 = 1458; // 0 - (2^16 -1) uint256 myUint256 = 47452848525; // uint goes from 8 to 256 taking steps of 8 and can hold max number which is equal to ( 2^n -1 ) // Signed Integers - can take negative as well as positive values Range = (-2^(n-1),2^n - 1) int8 myInt8 = -114; // -128 - 255 int16 myInt16 = -1458; // -32768 - 65535 int256 myInt256 = 47452848525; // int goes from 8 to 256 taking steps of 8 // address - Holds a 20 byte value (size of an Ethereum address). // address refers to a smart contract address // address payable refers to a wallet address which can recieve or send funds address myAddress; //Defaults to 0x0000000000000000000000000000000000000000 address public smartAddress = address(0x7EF2e0048f5bAeDe046f6BF797943daF4ED8CB47); address payable walletAddress = payable(0xBF4979305B43B0eB5Bb6a5C67ffB89408803d3e1); } Enter fullscreen mode Exit fullscreen mode

WARNING: This repository is currently undergoing updates and revisions to incorporate the latest information and advancements in Solidity programming. Please be advised that the content may not be up-to-date or accurate during this time. We expect the updates to be completed within the next 30 days, and appreciate your patience during this process. Thank you for your understanding.

Data Types

Solidity offers the programmer a rich assortment of built-in as well as user defined data types. Following table lists down seven basic C++ data types −

Type	Keyword	Values
Boolean	bool	true/false
Integer	int/uint	Signed and unsigned integers of varying sizes.
Integer	int8 to int256	Signed int from 8 bits to 256 bits. int256 is the same as int.
Integer	uint8 to uint256	Unsigned int from 8 bits to 256 bits. uint256 is the same as uint.
Fixed Point Numbers	fixed/ufixed	Signed and unsigned fixed point numbers of varying sizes.
Fixed Point Numbers	fixedMxN	Signed fixed point number where `M` represents number of bits taken by type and `N` represents the decimal points. M should be divisible by 8 and goes from 8 to 256. N can be from 0 to 80. fixed is same as fixed128x18.
Hexadecimal	address	Holds a 20 byte value (size of an Ethereum address).

example -

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.7;

contract MyTypes {
    bool myBool = true; // if bool value is not specified then it is false by default

    // Unsigned Integers - can only take 0 or positive values range =  0 - (2^n - 1)
    uint8 myUint8 = 84; // 0 - 255
    uint16 myUint16 = 1458; // 0 - (2^16 -1)
    uint256 myUint256 = 47452848525; // uint goes from 8 to 256 taking steps of 8 and can hold max number which is equal to ( 2^n -1 )

    // Signed Integers - can take negative as well as positive values Range = (-2^(n-1),2^n - 1)
    int8 myInt8 = -114; // -128 - 255
    int16 myInt16 = -1458; // -32768 - 65535
    int256 myInt256 = 47452848525; // int goes from 8 to 256 taking steps of 8

    // address - Holds a 20 byte value (size of an Ethereum address).
    // address refers to a smart contract address
    // address payable refers to a wallet address which can recieve or send funds
    address myAddress; //Defaults to 0x0000000000000000000000000000000000000000
    address public smartAddress = address(0x7EF2e0048f5bAeDe046f6BF797943daF4ED8CB47);
    address payable walletAddress = payable(0xBF4979305B43B0eB5Bb6a5C67ffB89408803d3e1);
}