是否有可能在阵列中的回声一个变量的值引用

Question

我需要通过类来拉输入的值，然后“回声”或引用，关联数组值

到目前为止，我的JavaScript是这样的：

var phone_code = document.getElementsByClassName('model').value; 
var phone = []; 
phone["6s"] = "23.52"; 
phone["5s"] = "9.88"; 
phone["5Se"] = "14.59"; 
phone["7"] = "28.49"; 
phone["s7e"] = "27.49"; 
phone["s7"] = "23.52"; 
phone["s6e"] = "21.04"; 
phone["s6"] = "18.56"; 
phone["a5"] = "12.61"; 
phone["j5"] = "7.65"; 
phone["a3"] = "8.64"; 
phone["j3"] = "5.17"; 
phone["p9"] = "16.08"; 
phone["p9lite"] = "8.64"; 

document.getElementById("phone-cost").innerHTML = phone[phone_code] 

和阵列输出为：

Your Phone would cost you £<span id="phone-cost"></span> per month 

但是，输出只是写着“不确定”，所以我不知道，如果JavaScript是问题，或者我需要进一步的回看在凝固酶原ss

phone_code需要使用class，因为它从表单启用/禁用的下拉列表中拉取，无论启用哪个下拉列表都需要使用。我想我的问题是，

phone[phone_code] 

是不是我应该如何引用变量，但我无法找到正确的方式一个明确的答案在一个阵列中格式化

感谢

Answer 1

两件事：

（1）.getElementsByClassName()返回一个类似数组的对象，而不是单个元素。 （2）尽管可以像你在代码中一样使用数组，但是使用普通对象要好得多。

见下文：

var btn = document.getElementById('getPrice'); 
 

 
btn.addEventListener('click', function() { 
 
    var phone_code = document.getElementsByClassName('model')[0].value; 
 

 
    var phone = {}; 
 
    phone["6s"] = "23.52"; 
 
    phone["5s"] = "9.88"; 
 
    phone["5Se"] = "14.59"; 
 
    phone["7"] = "28.49"; 
 
    phone["s7e"] = "27.49"; 
 
    phone["s7"] = "23.52"; 
 
    phone["s6e"] = "21.04"; 
 
    phone["s6"] = "18.56"; 
 
    phone["a5"] = "12.61"; 
 
    phone["j5"] = "7.65"; 
 
    phone["a3"] = "8.64"; 
 
    phone["j3"] = "5.17"; 
 
    phone["p9"] = "16.08"; 
 
    phone["p9lite"] = "8.64"; 
 

 
    document.getElementById("phone-cost").innerHTML = phone[phone_code]; 
 
});

<select class="model"> 
 
    <option value="6s">6s</option> 
 
    <option value="5s">5s</option> 
 
    <option value="5Se">5Se</option> 
 
</select> 
 
<input type="button" value="Get Price" id="getPrice" />Your Phone would cost you £<span id="phone-cost"></span> per month