Vue · Junior · Question 75 of 75

Why can a ref declared with `const` still change?

const count = ref(0)
count.value++ // works

✓Correct answer: const only prevents reassigning the variable; the ref object's .value is still mutable
2const makes the ref read-only, so this throws
3Refs must be declared with let

Explanation

Writing count = ref(1) would fail and also break every place that holds the old ref. Use readonly() to make a value truly read-only.

Further reading

Vue: Reactivity Fundamentals ↗

Test yourself

Take the Vue · Junior quiz: questions and options are shuffled, and you get a review of your mistakes at the end.