[j_s]

Nice! You've explained why this 'memory leak' could be by design - blame eval.

In fact, Chrome GC-ing unreferenced variables could break eval if they didn't cover that case.

[pcwalton]

Only direct `eval` though. As long as you don't see any calls to symbols named `eval`, you can implement this optimization.

See http://stackoverflow.com/questions/8694300/how-eval-in-javas...

[shardling]

Yeah, you could test this in the first example by replacing the string 'interval' with something like "alert(str.length)", and then redefining console.log=eval.

e: nm, I missed pcwalton's point -- when you call eval indirectly it isn't accessing the same scope. So redefining console.log couldn't access local variables like str. (I don't think?)

[masklinn]

Correct. Not only is eval not a good idea in general, but it's a very weird beast in javascript. See http://perfectionkills.com/global-eval-what-are-the-options/ for a very complete exposition of its weirdness.