Calculator

Summary

A working calculator UI with button clicks driving arithmetic logic — deceptively tricky once you handle decimals, chained operations and edge cases correctly. A calculator exposes state-management challenges such as input parsing, operator precedence, repeated operations, decimal handling, and recovery from invalid sequences.

• 1Handle operator chaining correctly (e.g. `5 + 3 * 2` in left-to-right or precedence order). Validate your understanding by applying it in a small practical example.
• 2Add keyboard support in addition to button clicks. Test the result on both a successful path and an invalid or unexpected input.
• 3Test edge cases: dividing by zero, multiple decimal points, clearing state.