闭包中的JavaScript For-loop alter loop语句

Question

I have a for-loop like this:

for (var i = 0, ii = 10; i < ii; i++) {
    var timer = setTimeout(function(i,timer) {
        return function() {
            clearTimeout(timer);
            if (condition) ii++;
        }
    }(i,timer), 1000);
}

What I am trying to do is increase the amount of times the for-loop is executed inside of the delayed closure in that for-loop.

The problem is that by the time that one of the 10 timer functions is executed, the loop has already finished. (I assume this is the problem)

I would like to know how I can alter ii within a such timeout function, without having to call the entire for-loop again. (The process has to stay in one loop)

Answer 1

You won't be able to do what you want exactly like that because whatever function is passed to setTimeout won't execute until the current function completes. For example, if you try:

setTimeout(function() {
    console.log('Hello!');
}, 100);
while (true) { }

You'll never see 'Hello!' because the current function will never complete. Instead, you might consider creating a function such that it acts upon something given your ii variable.

function doStuff(ii) {
    // Do some stuff given ii
    if (condition) {
        setTimeout(function() {
            doStuff(ii + 1);
        }, 1000);
    }
}

for (var i = 0; i < 10; i++) {
    doStuff(i);
}