Untitled

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.17;

contract ErrorTriageExercise {
/**
* Finds the difference between each uint with it's neighbor (a to b, b to c, etc.)
* and returns a uint array with the absolute integer difference of each pairing.
*/
function diffWithNeighbor(
uint _a,
uint _b,
uint _c,
uint _d
) public pure returns (uint[] memory) {
uint[] memory results = new uint[](3);

results[0] = _a > _b ? _a - _b : _b - _a;
results[1] = _b > _c ? _b - _c : _c - _b;
results[2] = _c > _d ? _c - _d : _d - _c;

return results;
}

/**
* Changes the _base by the value of _modifier. Base is always >= 1000. Modifiers can be
* between positive and negative 100;
*/
function applyModifier(
uint _base,
int _modifier
) public pure returns (uint returnValue) {
if(_modifier > 0) {
return _base + uint(_modifier);
}
return _base - uint(-_modifier);
}

/**
* Pop the last element from the supplied array, and return the popped
* value (unlike the built-in function)
*/
uint[] arr;

function popWithReturn() public returns (uint returnNum) {
if(arr.length > 0) {
uint result = arr[arr.length - 1];
arr.pop();
return result;
}
}

// The utility functions below are working as expected
function addToArr(uint _num) public {
arr.push(_num);
}

function getArr() public view returns (uint[] memory) {
return arr;
}

function resetArr() public {
delete arr;
}
}