Svelte · Junior · Question 33 of 76

Should a component mutate a prop object it received (not marked `$bindable`)?

✓Correct answer: No: the parent owns that state; Svelte warns about such mutations, so use callbacks or $bindable
2Yes, it's the normal way to update parent state
3Yes, but only arrays

Explanation

Mutating someone else's state makes data flow hard to follow. Let the owner change it.

Further reading

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