用函数中的值更新“全局”数组

Question

Yesterday, I needed help & was introduced to Closures (Im still struggling with that one).

At the start of the function, I created arrays, which need to be populated with values as created within the child function. I had an understanding that 'return' would simply return the values & update the array magically, apparently it doesnt happen that way. I tried push as well but again, no magic.

eEndDesigning.onclick = publicity;

function publicity() {
    var eCamerasArray = $(".cCameras").toArray();

    // this is the array that needs to be updated with the annon. func. inside setTimeout func.
    var iLeftPosArray = [];

    // this is the second array that needs to be updated
    var iTopPosArray = [];

    for (var i = 0; i < eCamerasArray.length; i++) {
        var timer = Math.floor(Math.random() * 300) + 100;
        (function(i) // a closure function
        {
            window.setTimeout(function() {
    // following two values are the ones that need to be fed back to 'global' arrays
                iLeftPosArray[i] = Math.floor(Math.random() * 139) + 360;
                iTopPosArray[i] = Math.floor(Math.random() * 160) + 100;
                $(eCamerasArray[i]).animate({
                    left: iLeftPosArray[i] + "px",
                    top: iTopPosArray[i] + "px"
                }, 100, "linear");
                return [iLeftPosArray[i], iTopPosArray[i]];
            }, timer);
        }(i));
    }
}

Answer 1

您可能需要将数组iLeftPosArray和iTopPosArray一个级别，因为它们当前不是全局的，但是具有函数的作用域。