I wouldn't say it's false, I would say it's no longer true in strict mode. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Errors/Deprecated_

I wouldn't say it's false, I would say it's no longer true in strict mode. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Errors/Deprecated_octal https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe... Javascript for many years has assumed a leading zero means an octal prefix, and it's only recently that behavior has changed. EDIT: Also your example does not disprove this. Here's another example that you should try running in the console: 011 === 11; // false 011; // 9