Svelte · Junior · Question 19 of 76

Why shouldn't you use the index as the key in `{#each}`?

✓Correct answer: When items are added, removed or reordered, indexes shift and Svelte matches the wrong DOM nodes and state
2Index keys are not supported and cause a compile error
3Index keys make the list render twice

Explanation

Use a stable unique identifier like item.id. The index is available as the second variable: {#each items as item, i (item.id)}.

Further reading

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