The nullish coalescing operator provides a precise way to handle null and undefined values without affecting other falsy values like empty strings or zero. As the creator of CoreUI, a widely used open-source UI library, I’ve used nullish coalescing extensively in JavaScript applications for safer default value assignment. From my 25 years of experience in web development, the nullish coalescing operator (??) is more reliable than logical OR (||) for default values because it only triggers for null and undefined. This operator prevents unexpected behavior with legitimate falsy values.

Using optional chaining in JavaScript safely accesses nested object properties and methods without throwing errors when intermediate values are null or undefined. With over 25 years of experience in software development and as the creator of CoreUI, I’ve used optional chaining extensively for API response handling, configuration access, and defensive programming. From my expertise, the most reliable approach is using the ?. operator to chain property access with automatic null checking at each level. This ES2020 feature eliminates verbose null checking code while providing safe navigation through complex object structures.