javascript - 从下拉菜单中获取值后，我可以将其与字符串进行比较吗？

Question

<分区>

Answer 1

Fiddle

您忘记为您的选择添加一个 ID。我添加了 <select name="singleMultiContainer" id="singleMultiContainer">尽管您在脚本中“寻找它”，但它没有 ID。
你也有一些拼写错误，我修正了我发现的那些，所以请检查这是否是你想要的。

超链接

<form id="suspendedProperties">
    <p>
        <h4>Select Station:
    <select name="stationDropdown">
        <option value="50028000">Tanama</option>
        <option value="60008001">Example Riv1</option>
        <option value="60008002">Example Riv2</option>
        <option value="60008003">Example Riv3</option>
        <option value="60008004">Example Riv4</option>
     </select>
     </h4>
    </p>
    <p>Select Sample Medium:
        <select name="sampleMediumDropdown">
            <option value="Wer">Wer</option>
            <option value="WSQ">WSQ</option>
        </select>
    </p>
    <p>Begin Date
        <input type="date" />
    </p>
    <p>Hydrologic Event:
        <select name="hydroEvent">
            <option value="1">Example 1</option>
            <option value="2">Example 2</option>
            <option value="3">Example 3</option>
            <option value="4">Example 4</option>
            <option value="5">Example 5</option>
            <option value="6">Example 6</option>
        </select>
    </p>
    <p>Add:
        <input type="number" size="" />
        <select name="singleMultiContainer" id="singleMultiContainer">
            <option value="single">Single container sample</option>
            <option value="multi">Multiple sets container</option>
        </select>
    </p>
    <p>Analyses Requested:(Applies to all samples)
        <br/>
    </p>
    <div id="analyses">
        <input type="checkbox" name="analysis" value="C">Concentration</input>
        <input type="checkbox" name="analysis" value="SF">Sand-fine break**</input>&nbsp;
        <input type="checkbox" name="analysis" value="SA">Sand analysis**</input>
        <br/>
        <input type="checkbox" name="analysis" value="T">Turbidity</input>
        <input type="checkbox" name="analysis" value="LOI">Loss-on-ignition**</input>&nbsp;
        <input type="checkbox" name="analysis" value="DS">Dissolve solids</input>
        <br/>
        <input type="checkbox" name="analysis" value="SC">Specific conductance</input>
        <input type="checkbox" name="analysis" value="Z">Full-size fractions**</input>
    </div>
    <input type="button" value="Back" onClick="window.location='SED_WE.html'" />
    <input type="button" value="Next" id="nextButton" onClick="window.location='SampleInfo.html'" />
</form>

JS

// JavaScript Document
var singleMultiContainer = document.getElementById("singleMultiContainer");
var singleMultiValue = singleMultiContainer.options[singleMultiContainer.selectedIndex].value;
var nextButton = document.getElementById("nextButton");
var multipleSetWindow = "window.location='multiSet.html'"

if (singleMultiValue == "multi") {
    document.getElementById("nextButton").setAttribute("onclick", "window.location='multiSet.html'");
} else {
    alert("notworking");
}