Replace Without Mutation
Replace Without Mutation
Replacing an array item by index is direct, but doing it on the input array changes data that other code may still be using. The safer pattern is to copy the array first and perform the replacement on the copy.
This is common when a single item in a list changes but the old list is still needed for comparison, rendering, or rollback.
Your task: Complete withReplacement so it returns a new array where the item at index has been replaced by value. If the index is outside the array, return a copy with the same contents.
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Replace Without Mutation
Replacing an array item by index is direct, but doing it on the input array changes data that other code may still be using. The safer pattern is to copy the array first and perform the replacement on the copy.
This is common when a single item in a list changes but the old list is still needed for comparison, rendering, or rollback.
Your task: Complete withReplacement so it returns a new array where the item at index has been replaced by value. If the index is outside the array, return a copy with the same contents.