Javascript-如何将 onClick 函数结果保存到两个不同的变量中？

Question

我是 JavaScript 的学习者。我有两组下拉选项，并希望在单击一个按钮（更新）时将下拉选择中的更改保存为两个不同的变量。

这是我获取变量的函数：

function jsDropDown() {

        //Get the start date upon changing the button

        var start_date = document.getElementById("days1").value + "-" + 

            document.getElementById("months1").value + "-" +

            document.getElementById("years1").value;

        var end_date = document.getElementById("days2").value + "-" + document.getElementById("months2").value + "-" +

            document.getElementById("years2").value;

    }

这是一个小提琴：https : //jsfiddle.net/TomaSaha/eh1w7k6a/

这个想法是当用户选择 01-February-2019 时，将其保存为 start_date，当用户选择 31-December-2019 时，将其保存为 end_date。

Answer 1

几点：1）您的年份下拉文本与值不同，1982 映射为 1995，依此类推。2）你的函数是正确的，但不能被调用，因为小提琴有一些不同的设置，结果它抛出referenceError（函数未定义）所以你有两个选择：(a) 在脚本标签中移动你的函数或者(b) 使用document.readyjquery 中的函数见演示 2(a) https://jsfiddle.net/fgrt1qvh/1/

Answer 2

请查看上面的快照，在控制台中查看它是否按照您想要的方式完美运行。并找到下面的代码<Div class="dropDown1">&nbsp; Day: <select name="days" id="days1">&nbsp; &nbsp; <option value="01">01</option>&nbsp; &nbsp; <option value="02">02</option>&nbsp; &nbsp; <option value="03">03</option>&nbsp; </select>&nbsp; Month: <select name="months" id="months1">&nbsp; &nbsp; <option value="January">January</option>&nbsp; &nbsp; <option value="February">February</option>&nbsp; &nbsp; <option value="March">March</option>&nbsp; </select>&nbsp; Year: <select name="years" id="years1">&nbsp; &nbsp; <option value="1995">1995</option>&nbsp; &nbsp; <option value="1996">1996</option>&nbsp; &nbsp; <option value="1997">1997</option>&nbsp; </select></Div>End Date <Div class="dropDown2">&nbsp; Day: <select name="days" id="days2">&nbsp; &nbsp; <option value="01">01</option>&nbsp; &nbsp; <option value="02">02</option>&nbsp; &nbsp; <option value="03">03</option>&nbsp; </select>&nbsp; Month: <select name="months" id="months2">&nbsp; &nbsp; <option value="January">January</option>&nbsp; &nbsp; <option value="February">February</option>&nbsp; &nbsp; <option value="March">March</option>&nbsp; </select>&nbsp; Year: <select name="years" id="years2">&nbsp; &nbsp; <option value="1995">1995</option>&nbsp; &nbsp; <option value="1996">1996</option>&nbsp; &nbsp; <option value="1997">1997</option>&nbsp; </select></Div><button onclick="myFunction()">Update</button><script>function myFunction() {debugger&nbsp; //Get the start date upon changing the button&nbsp; var start_date = document.getElementById("days1").value + "-" + document.getElementById("months1").value + "-" +&nbsp; &nbsp; document.getElementById("years1").value;&nbsp; var end_date = document.getElementById("days2").value + "-" + document.getElementById("months2").value + "-" +&nbsp; &nbsp; document.getElementById("years2").value;console.log('start_date', start_date);console.log('end_date', end_date)}</script>