Algorithm for javascript pre-defined functions (parseInt, parseFloat, isNaN, etc.)

Question

What is the best way, if even possible, to see the underlying code for the predefined functions in Javascript. Is there documentation that shows how these were coded, or an

Answer 1

Those functions are implementation specific depending on browser, and are not written in JS (unless somebody's decided to write a browser engine in JS). The code is not guaranteed to be the same across environments, though they do have to (in theory) adhere to the ECMAScript specification for their behavior.