Functions

Safe Callback Calls

Safe Callback Calls

MediumFunctionsPRO

Practice JavaScript callback safety by checking whether a value is callable before invoking it. This medium function exercise focuses on typeof checks, optional callbacks, fallback returns, and avoiding runtime errors.

What you'll practice

  • Work with JavaScript callback safety by checking whether a value is callable before invoking it
  • This medium function exercise focuses on typeof checks
  • Optional callbacks
  • Fallback returns
  • Avoiding runtime errors

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