Question

您好我还有问题。我构建了js，您可以按以下顺序添加数字 - ＆GT; 50-20并且在选择中你得到的数字从20,21,22,23,24,25到50开始。我想改变代码的顺序当你把50-20的结果放在select中时应该从50开始并从50,49,48开始计算....直到20。

以下是JSFIDDLE上的代码。问题可能非常愚蠢，但现在我很困惑：X。

HTML


<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8" />
  <title>jQuery</title>
    <link rel="stylesheet" type="text/css" href="css/style.css"/>
    <link rel="stylesheet" type="text/css" href="css/alertify.core.css"/>
    <link rel="stylesheet" type="text/css" href="css/alertify.default.css"/>
    <link href='http://fonts.googleapis.com/css?family=Open+Sans' rel='stylesheet' type='text /css'>


</head>
<body>
    <div class="wrapper">
        <h1>Enter values</h1>

        <p class="example">number - number</p>

        <input type="text" name="field" id="keys" class="button"/>

        <a href="javascript:void(0);" id="calculate" class="press">Push!</a>

        <div id="select_result">
            <!-- Generate Dynamic Select! -->
        </div>

    </div><!-- End wrapper div -->

    <script src="js/jquery-1.11.0.js"></script>
    <script src="js/task.js"></script>
    <script src="js/alertify.min.js"></script>
</body>
</html>








JS


     $(document).ready(function () {

            function calculateResult(){

                var value_1 = parseInt( $("#keys").val().split("-")[0] );
                var value_2 = parseInt( $("#keys").val().split("-")[1] );

                if( $("#keys").val().indexOf("-") == "-1" ){
                    // alert dialog
                    alertify.alert("Въведи две цифри с тире!");

                    return;
                } else if ( typeof value_1 == 'undefined' || typeof value_2 == 'undefined' || value_1 == "" || value_2 == "" || isNaN(value_1) || isNaN(value_2)) {
                    // error notification
                    // shorthand for alertify.log("Notification", "error");
                    alertify.error("Въведи две цифри!");

                    return;

                }


                var select_string = "";
                select_string = "<select>";
                if ( value_1 > value_2 ){
                    for( i = value_2; i <= value_1; i++ ){
                        select_string += "<option>" + i + "</option>";
                    }

                } else if ( value_1 < value_2 ){
                    for( i = value_1; i >= value_2; i++ ){
                        select_string += "<option>" + i + "</option>";
                    }
                } else if ( value_1 == value_2 ){
                    select_string += "<option>" + value_1 + "</option>";
                }
                select_string += "</select>";

                $("#select_result").html(select_string);

            }


            $("#calculate").on("click", function(){
                calculateResult();

            });
            $(document).on("keypress", function (e) {
                if(e.which == 13) {
                    calculateResult(e);

                }
            });
        });

谢谢

Answer 1

试试这个：

for( i = value_1; i >= value_2; i-- ){
      select_string += "<option>" + i + "</option>";
      console.log(select_string);
}

<强> DEMO

如何更改数字的顺序？

1 个答案: