uint vs uint256
Below are the differences between uint and uint256:
| Range | Default size | Typical use cases | |
|---|---|---|---|
| uint | 0 to 2^256-1 | 256 bits | General-purpose unsigned integer type |
| uint8 | 0 to 2^8-1 | 8 bits | Small unsigned integers |
| uint16 | 0 to 2^16-1 | 16 bits | Representing values that require more bits than uint8 |
| uint32 | 0 to 2^32-1 | 32 bits | Representing values that require more bits than uint16 |
| uint64 | 0 to 2^64-1 | 64 bits | Representing values that require more bits than uint32 |
| uint128 | 0 to 2^128-1 | 128 bits | Large unsigned integers |
| uint256 | 0 to 2^256-1 | 256 bits | Large unsigned integers |
Solidity’s uint256 and uint are equal. Size and value range distinguish uint from other uint types. Using a smaller uint type may save gas and storage space for variables with a narrower range. If a variable only has to represent numbers from 0 to 255, using uint8 instead of uint256 saves gas and storage.
If the variable needs more values, uint256 is needed. Overflow and underflow issues occur when a smaller uint type represents a bigger number. Hence, the uint type depends on the use case and variable range.
Example:
Below is the Solidity program to implement integers:
Solidity
// SPDX-License-Identifier: MITpragma solidity ^0.8.0;contract IntegerExample { uint256 public myUint; int256 public myInt; function setValues(uint256 _myUint, int256 _myInt) public { myUint = _myUint; myInt = _myInt; } function multiply(uint256 _value) public view returns (uint256) { return myUint * _value; }} |
Explanation: In this example, we define a contract called IntegerExample that has two state variables, myUint and myInt, both of which are assigned the value 0 by default. We also define two functions, setValues and multiply.
- The setValues function takes two input parameters, a uint256, and an int256, and sets the values of myUint and myInt to those input values, respectively.
- The multiply function takes a uint256 input parameter _value and returns the product of myUint and _value.
Output:
Remix Output
Solidity – Integers
Integers help store numbers in smart contracts. Solidity provides two types of integers:
- Signed Integers: Signed integers can hold both positive and negative values, ranging from -2 ^ 255 to 2 ^255 – 1.
- Unsigned Integers: Unsigned integers can hold only integer values equal to or greater than zero, ranging from 0 to 2 ^256 – 1.
Contact Us