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Multiple ChoiceIntermediate 30s

Once Function Pattern

Choose the best answer for: ensuring single execution
Options
  1. 1Once patterns use generators to yield the value only one time
  2. 2Once is a built-in method on Function.prototype in JS
  3. 3Once requires a class to wrap the function and guard calls
  4. 4A closure with a 'called' flag ensures function runs only once

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