Challenge 21

Loop optimization

GasGas optimization

Challenge

Review the loop and identify the gas-heavy pattern that could be avoided in a large array operation.

Starter code

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract LoopStudy {
  uint256[] public values;

  function total() public view returns (uint256) {
    uint256 sum = 0;
    for (uint256 i = 0; i < values.length; i++) {
      sum += values[i];
    }
    return sum;
  }
}

Show hint

Look for repeated external costs or unnecessary operations inside the loop.