javascript - for循环中的Javascript数组返回未定义

Question

当我用 for 循环循环这个数组时，它以某种方式给了我 undefined in

updateField(this.value, vehicles[i]+"_brand"

尽管

$("#"+vehicles[i]+"_year").change(function(){

确实获得了数组的正确值。这怎么可能，我该如何解决？

var vehicles = new Array();
    vehicles[0] = "auto";
    vehicles[1] = "truck";
    vehicles[2] = "motor";

for(var i = 0;i < vehicles.length;i++){
    $("#"+vehicles[i]+"_year").change(function(){
       updateField(this.value, vehicles[i]+"_brand", 1, 2, this.parentNode.id), resetBelow(0,'auto'), show('auto_brand');
    });
}

Answer 1

将再次评估将触发更改事件的时间vehicles[i]，您将获得最后一个值i.

改变

vehicles[i]+"_brand"

至

this.id.split('_')[0]+"_brand"

Answer 2

看起来你在我应该分号的地方有逗号：

updateField(this.value, vehicles[i]+"_brand", 1, 2, this.parentNode.id); resetBelow(0,'auto'); show('auto_brand');

...或者您的updateField()函数可能有更多参数，而您只是过早地关闭了该函数？