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Cyfrin / 2023-07-foundry-defi-stablecoin

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`++i`/`i++` should be `unchecked{++i}`/`unchecked{i++}` when it is not possible for them to overflow, as is the case when used in `for`- and `while`-loops #1139

Open codehawks-bot opened 1 year ago

codehawks-bot commented 1 year ago

++i/i++ should be unchecked{++i}/unchecked{i++} when it is not possible for them to overflow, as is the case when used in for- and while-loops

Severity

Gas Optimization / Informational

Relevant GitHub Links

https://github.com/Cyfrin/2023-07-foundry-defi-stablecoin/tree/main/src/DSCEngine.sol

Summary

++i/i++ should be unchecked{++i}/unchecked{i++} when it is not possible for them to overflow, as is the case when used in for- and while-loops

Vulnerability Details

The unchecked keyword is new in solidity version 0.8.0, so this only applies to that version or higher, which these instances are. This saves 30-40 gas per loop

Instances (2):

File: src/DSCEngine.sol

119:         for (uint256 i = 0; i < tokenAddresses.length; i++) {

355:         for (uint256 i = 0; i < s_collateralTokens.length; i++) {

Link to code - https://github.com/Cyfrin/2023-07-foundry-defi-stablecoin/tree/main/src/DSCEngine.sol

Tools Used

Code Review using VSCode

Recommendations

Use unchecked{++i}/unchecked{i++} in loops