The ECMAScript proposal “String padding” by Jordan Harband & Rick Waldron is part of ECMAScript 2017. This blog post explains it. Padding strings # Use cases for padding strings include: Displaying tabular data in a monospaced font. Adding a count or an ID to a file name or a URL: 'file 001.txt' Aligning console output: 'Test 001: ✓' Printing hexadecimal or binary numbers that have a fixed number