a strict mode in ECMAScript 5 forbids octal syntax. The octal syntax isn't part of ECMAScript 5, but it's supported in all browsers by prefixing the octal number with a zero: 0644 === 420 and "\045" === "%".
In ECMAScript 2015 Octal number is supported by prefixing a number with "0o".
Why is this behavior. Please elaborate ?
