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Spread, Rest, and Immutable Updates

8 exercisesIntermediate

The ... syntax has two related jobs: spread expands existing values into a new array or object, while rest collects the values left over by a pattern or parameter list.

const profile = { name: "Noor", theme: "light" };
const updatedProfile = { ...profile, theme: "dark" };

const scores = [12, 18];
const allScores = [...scores, 21];

console.log(profile.theme);        // light
console.log(updatedProfile.theme); // dark

You’ll copy and combine collections, gather remaining values, and perform immutable updates. Creating a new value instead of mutating the old one makes changes easier to track and prepares you for state-driven interfaces.

Copy an Array with SpreadStart Copy an Object with SpreadStart Collect the Rest of an ObjectStart Combine Arrays with SpreadStart Repair an Immutable Object UpdateStart Add an Array Item ImmutablyStart Use Rest ParametersStart Immutable Dashboard UpdateStart

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