Replacing all occurrences of substrings is essential for data cleaning, text processing, template rendering, and implementing features like find-and-replace functionality in JavaScript applications. With over 25 years of experience in software development and as the creator of CoreUI, I’ve implemented global string replacement in components like text editors, data formatters, and content processors where comprehensive text transformation is required. From my extensive expertise, the most modern and straightforward solution is using the ES2021 replaceAll() method, which handles all instances in a single operation. This approach is intuitive, efficient, and eliminates the need for complex regular expressions or iterative replacements.