javascript - Why does the value of typeof null change inside a loop?

Question

Executing this snippet in the Chrome console:

function foo() {
    return typeof null === 'undefined';
}
for(var i = 0; i < 1000; i++) console.log(foo());

Answer 1

There is a chromium bug open for this:

Issue 604033 - JIT compiler not preserving method behavior

So yes It's just a bug!