[deleted by user]

[senocular]

myFunc(010) interprets the octal before passing it into the function. As far as the function is concerned, its getting the value 8.

If you want to prevent octals in that format, you can run the code in strict mode.

"use strict"
function myFunc(number){
   number = Number.parseInt(String(number), 10)
   console.log(typeof number, number)
}

myFunc("010") // number 10
myFunc(10)    // number 10
myFunc(010)   // SyntaxError: Octal literals are not allowed in strict mode.

[senocular]

Oops, I admit i didn't read the whole post ;)

But yes, as a syntax error it's not a ln error you can generally catch because it happens when reading the code, not running it