Javascript 如何将HTML文本与if/else语句中数组外的字符串进行比较？

此测验中的用户可以选择一个名称：

<p>Wie is jouw allergrootste vijand</p>
<input type="radio" name="vijand" value="Loki" class="vijand"> Loki
<input type="radio" name="vijand" value="Joker" class="vijand"> Joker
<input type="radio" name="vijand" value="Two Face" class="vijand"> Two Face
<input type="radio" name="vijand" value="Red Skull" class="vijand"> Red Skull
<input type="radio" name="vijand" value="Thanos" class="vijand"> Thanos
<input type="radio" name="vijand" value="Killmonger" class="vijand"> Killmonger
<input type="radio" name="vijand" value="Black Adam" class="vijand"> Black Adam
<input type="radio" name="vijand" value="Hela" class="vijand"> Hela

我做错了什么？

您以错误的方式使用indexOf。你想要：

function vijand(){
    var vijanden = ['Loki', 'Joker', 'Two Face', 'Red Skull', 'Thanos', 'Killmonger', 'Black Adam', 'Hela'];
    var vijandNummer;

    var vijandenValue = document.querySelector('input[name=vijand][checked]').value;

    if(['Loki', 'Joker', 'Two Face', 'Red Skull'].indexOf(vijandValue) !== -1) {
        vijandNummer = 1
    }

    if(['Thanos', 'Killmonger', 'Black Adam', 'Hela'].indexOf(vijandValue) !== -1) {
        vijandNummer = 0
    }

    return vijandNummer;
}

var index = vijanden.indexOf(keuze); // for keuze = 'Hela', index = 7

然后：

---

假设根据您的代码，如果选择前四位英雄中的任何一位，vijandNummer必须为1，否则为0。

您应该阅读indexOf上的文档

var index = vijanden.indexOf(keuze); // for keuze = 'Hela', index = 7

vijandNummer = index < 4 ? 1 : 0;