Using ++i consumes less gas than i++

[code423n4]

Handle

Reigada

Vulnerability details

Impact

In all the loops, the variable i is incremented using i++. It is known that using ++i costs less gas per iteration than i++.

Proof of Concept

AirdropDistributionMock.sol:97: for (uint i = 0; i < airdropArray.length; i++) {
SwapUtils.sol:433: for (uint256 i = 0; i < self.pooledTokens.length; i++) {
SwapUtils.sol:535: for (uint256 i = 0; i < numTokens; i++) {
SwapUtils.sol:549: for (uint256 i = 0; i < MAX_LOOP_LIMIT; i++) {
SwapUtils.sol:574: for (uint256 i = 0; i < numTokens; i++) {
SwapUtils.sol:585: for (uint256 i = 0; i < MAX_LOOP_LIMIT; i++) {
SwapUtils.sol:648: for (uint256 i = 0; i < numTokens; i++) {
SwapUtils.sol:852: for (uint256 i = 0; i < numTokens; i++) {
SwapUtils.sol:872: for (uint256 i = 0; i < MAX_LOOP_LIMIT; i++) {
SwapUtils.sol:970: for (uint256 i = 0; i < self.pooledTokens.length; i++) {
SwapUtils.sol:1031: for (uint256 i = 0; i < numTokens; i++) {
SwapUtils.sol:1190: for (uint256 i = 0; i < self.pooledTokens.length; i++) {
SwapUtils.sol:1230: for (uint256 i = 0; i < self.pooledTokens.length; i++) {
SwapUtils.sol:1341: for (uint256 i = 0; i < amounts.length; i++) {
SwapUtils.sol:1440: for (uint256 i = 0; i < self.pooledTokens.length; i++) {
SwapUtils.sol:1449: for (uint256 i = 0; i < self.pooledTokens.length; i++) {
SwapUtils.sol:1471: for (uint256 i = 0; i < self.pooledTokens.length; i++) {
SwapUtils.sol:1492: for (uint256 i = 0; i < self.pooledTokens.length; i++) {
Vesting.sol:116: for (uint256 i = 0; i < timelocks[_addr].length; i++) {
Vesting.sol:148: for (uint256 i = 0; i < timelocks[_addr].length; i++) {
Vesting.sol:170: for (uint256 i = benVestingIndex[_addr]; i < timelocks[_addr].length; i++) {
helper/test/TestSwapReturnValues.sol:27: for (uint8 i; i < n; i++) {
helper/test/TestSwapReturnValues.sol:95: for (uint8 i = 0; i < n; i++) {
helper/test/TestSwapReturnValues.sol:102: for (uint8 i = 0; i < n; i++) {
Swap.sol:158: for (uint8 i = 0; i < _pooledTokens.length; i++) {
PublicSaleBatchWithdraw.sol:29: for (uint i = 0; i < arrayDays.length; i++) {
PublicSaleBatchWithdraw.sol:36: for (uint i = 0; i < length; i++) {
AirdropDistribution.sol:507: for (uint i = 0; i < airdropArray.length; i++) {

Tools Used

Manual testing

Recommended Mitigation Steps

Use ++i instead of i++ to increment the value of an uint variable.

[chickenpie347]

Duplicate of #12

[0xean]

Not a duplicate of #12 which suggests unchecked, this has to do with the pre-increment vs increment.