Checking for NaN values is crucial for input validation, error handling, mathematical operations, and implementing robust features like form validation or data processing in JavaScript applications. With over 25 years of experience in software development and as the creator of CoreUI, I’ve implemented NaN checking extensively in components like calculators, form validators, and data processors where detecting invalid numeric operations prevents errors and ensures reliable functionality. From my extensive expertise, the most accurate and recommended approach is using Number.isNaN(), which performs a strict NaN check without type coercion. This method is precise, avoids common pitfalls of the older isNaN() function, and provides reliable detection of actual NaN values.

Checking if strings are empty is fundamental for form validation, data processing, conditional logic, and implementing features like required field validation or content display controls in JavaScript applications. With over 25 years of experience in software development and as the creator of CoreUI, I’ve implemented empty string checks extensively in components like form inputs, search bars, and content validators where ensuring data presence is crucial for user experience and application logic. From my extensive expertise, the most reliable and performant solution is checking the string’s length property against zero. This approach is direct, efficient, and handles the specific case of empty strings without ambiguity.