Integer Arthimetic.md

43 - Integer Arthimetic

Integers in Solidity are restricted to a certain range.

For example, with uint32, this is 0 up to 2**32 - 1.

There are two modes in which arithmetic is performed on these types: The “wrapping” or “unchecked” mode and the “checked” mode.

By default, arithmetic is always “checked”, which means that if the result of an operation falls outside the value range of the type, the call is reverted through a failing assertion.

You can switch to “unchecked” mode using unchecked { ... }. This was introduced in compiler version 0.8.0.

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Slide Screenshot

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Slide Deck

• E.g.: uint256
  • Range: 0 -> 2**256-1
• Underflow/Overflows -> Wrapping
• Solidity < 0.8.0 -> SafeMath
• Solidity >= 0.8.0 -> Built-in
• Checked vs. Unchecked

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References

• Youtube Reference

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Tags

Comparison & Bitwise Logic