Submission Details
Severity:
Cache array lengths when using for loops
Summary
Cache array lengths when using for loops to save gas.
Vulnerability Details
Since the for loops don't modify array.length, it is more gas-efficient to cache it in some local variable and use that variable instead, like in the following example:
contract C
{
uint[] array;
function f() public
{
uint array_length = array.length;
for (uint i = 0; i < array_length; i++)
{
// code that does not modify length of `array`
}
}
}
Tools Used
Slither
Recommendations
When using for loops on arrays cache it's length in a local variable and use that within the for loop
Rewards breakdown
nSLOC
239This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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