Restricting eval() to a narrow scope

Question

I have a javascript file that reads another file which may contain javascript fragments that need to be eval()-ed. The script fragments are supposed to conform to a strict s

Answer 1

Don't execute code you don't trust. Globals will always be accessible. If you do trust the code, you can execute it with particular variables in it's scope as follows:

(new Function("a", "b", "alert(a + b);"))(1, 2);

this is equivalent to:

(function (a, b) {
    alert(a + b);
})(1, 2);