Javascript For循环索引返回 "[object Object] - undefined"

Question

我正在尝试对多个元素运行一个函数，所以我正在使用 for 循环。我不明白为什么我没有得到任何值。

    var i;
var aFields = ["#business1A","#business1B","#business1C","#business1D","#business2A","#business2B","#business2C","#business2D",
                "#business3A","#business3B","#business3C","#business3D","#business4A","#business4B","#business4C","#business4D",
                "#business5A","#business5B","#business5C","#business5D","#business6A","#business6B","#business6C","#business6D"];
for (i = 0; i < aFields.length; i++) {
    $(aFields[i]).keyup(function(){
        alert($(aFields[i]+'Warning') + " - " +$(aFields[i]).val());
    });
}

Answer 1

试试这个:

var i;
var aFields = ["#business1A","#business1B","#business1C","#business1D","#business2A","#business2B","#business2C","#business2D",
                "#business3A","#business3B","#business3C","#business3D","#business4A","#business4B","#business4C","#business4D",
                "#business5A","#business5B","#business5C","#business5D","#business6A","#business6B","#business6C","#business6D"];
for (i = 0; i < aFields.length; i++) {
  (function(j){
    $(aFields[j]).keyup(function(){
        alert(($(this).attr('id')+'Warning') + " - " +$(this).val());
    });
  })(i);
}