Checking if strings end with specific suffixes is essential for file extension validation, URL path checking, data format detection, and implementing features like file type filtering or domain validation in JavaScript applications. With over 25 years of experience in software development and as the creator of CoreUI, I’ve implemented suffix checking extensively in components like file upload systems, URL validators, and content processors where determining string endings is crucial for proper data handling and user experience. From my extensive expertise, the most modern and straightforward solution is using the ES6 endsWith() method, which provides a clear boolean result. This approach is intuitive, performant, and specifically designed for suffix detection with excellent readability.