React · Junior · Question 15 of 75

What's the right way to add an item to an array in state?

1items.push(item); setItems(items);
✓Correct answer: setItems([...items, item]);
3setItems(items.concat).push(item);

Explanation

State must be updated immutably - by creating a new array. push mutates the existing array, and the reference doesn't change. Non-mutating methods: spread, concat, filter, map, slice, toSorted(). Removal: items.filter(i => i.id !== id).

What's the right way to add an item to an array in state?

Explanation

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