Append Without Mutation
Append Without Mutation
Some array methods change the existing array, while other patterns create a separate array with the update applied. That distinction matters when previous state must stay trustworthy, such as UI state, undo history, or cached data.
For this helper, the returned array should include the new item at the end. The input array should still contain exactly what it contained before the function was called.
Your task: Complete withAppended so it returns a new array with item added at the end. Do not change the array passed into the function.
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Append Without Mutation
Some array methods change the existing array, while other patterns create a separate array with the update applied. That distinction matters when previous state must stay trustworthy, such as UI state, undo history, or cached data.
For this helper, the returned array should include the new item at the end. The input array should still contain exactly what it contained before the function was called.
Your task: Complete withAppended so it returns a new array with item added at the end. Do not change the array passed into the function.