const mutation in JavaScript

What this snippet does

const prevents reassignment of the variable itself, but the object it points to is still mutable.

Expected output

{ name: 'Alice', age: 31, email: 'alice@example.com' }
const only locks the binding, not the contents

Why practise typing this

Typing variables code builds muscle memory for the symbols and indentation JavaScript uses most, which prose-based typing tests never cover. DevType measures your words per minute and accuracy on this snippet and tracks the individual characters you mistype, so later lessons can target them.

More JavaScript practice

• let vs constVariables · beginner
• const configVariables · beginner
• var hoistingVariables · beginner
• var scope leakVariables · intermediate
• typeof operatorTypes · beginner
• typeof nullTypes · beginner