Track a Balance

MediumFoundationsPRO

Practice JavaScript variables and arithmetic by tracking a balance that changes through several updates. This medium exercise asks you to preserve the starting value, update mutable state, and calculate the net change without mixing original and final values.

What you'll practice

Work with JavaScript variables and arithmetic by tracking a balance that changes through several updates
Preserve the starting value
Update mutable state
Calculate the net change without mixing original and final values

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