What's the difference between int and uint in Solidity

I have been learning blockchain and solidity for some months and I wanted to share my knowledge on the same. Today I want to talk about INT and UINT in Solidity.

Introduction

Solidity is a programming language used to write smart contracts on the Ethereum blockchain. Solidity has a range of data types to work with, including integers (int) and unsigned integers (uint). In this article, we will explore these data types, how they work, and their limitations.

Integers (int)

Integers (int) are signed data types in Solidity, which means they can hold both positive and negative values. Integers can be declared with a number of bits, such as int8, int16, int32, int64, and so on, up to int256.

Here’s an example of declaring an integer variable in Solidity:

int256 myInt = 10;

This creates a signed integer variable with 256 bits that store the value 10.

Unsigned Integers (uint)

Unsigned integers (uint) are similar to integers, but they can only store positive values. Like integers, unsigned integers can be declared with a number of bits, such as uint8, uint16, uint32, uint64, and so on, up to uint256.

Here’s an example of declaring an unsigned integer variable in Solidity:

uint256 myUint = 20;

This creates an unsigned integer variable with 256 bits that store the value 20.

Limitations

Both integers and unsigned integers have limitations when it comes to their size. In Solidity, the maximum value an int can store is 2²⁵⁵-1, and the maximum value a uint can store is 2²⁵⁶-1. It is important to keep in mind these limitations when working with large numbers.

In addition, Solidity has no support for floating-point numbers, which can cause issues when dealing with decimals. Developers can work around this limitation by using fixed-point arithmetic or libraries such as OpenZeppelin’s SafeMath.

Conclusion

Integers (int) and unsigned integers (uint) are essential data types in Solidity, used to store numerical values in smart contracts. Understanding the differences and limitations of these data types is important for developers working on Ethereum-based applications. By keeping these limitations in mind, developers can write more robust and efficient smart contracts.