问JavaScript中的内存泄漏和闭包-何时以及为什么？

EN

var theThing = null;
var cnt = 0; // helps us to differentiate the leaked objects in the debugger
var replaceThing = function () {
    var originalThing = theThing;
    var unused = function () {
        if (originalThing) // originalThing is used in the closure and hence ends up in the lexical environment shared by all closures in that scope
            console.log("hi");
    };
    // originalThing = null; // <- nulling originalThing here tells V8 gc to collect it 
    theThing = {
        longStr: (++cnt) + '_' + (new Array(1000000).join('*')),
        someMethod: function () { // if not nulled, original thing is now attached to someMethod -> <function scope> -> Closure
            console.log(someMessage);
        }
    };
};
setInterval(replaceThing, 1000);