如何检查是否选中了另一个复选框并在添加条件的情况下再次执行该函数?

Question

所以我的任务是创建一个菜单，用户可以在四种面条、四种主菜和三种配菜之间进行选择。配菜会使主菜的价格增加一倍。问题是，用户每选中一条面条，总价格就会增加50%。因此，如果用户支付了120美元并选择了两种面条，那么它将是180美元。

我知道复选框将调用两个函数，但是我不知道只有当有两个或更多的复选框被选中时它将如何工作。有人可以帮助或指导我如何实际执行这个吗?

小提琴

function pmodel() {
Model();
finalCost();
}
function Model() {
if (document.querySelector('input[name="NDLS"]:checked')) {
document.getElementById("MMD").disabled = false;
document.getElementById("ADDONS").disabled = false;
} else {
document.getElementById("MMD").disabled = true;
document.getElementById("ADDONS").disabled = true;
}
}
function total() {
var selected1 = document.querySelector('input[name="MD"]:checked').value;
var selected2 = document.querySelector('input[name="ADDONS"]:checked').value;
//var totals = 0;
totals = (selected1 * selected2);
finalCost(totals);
}

function finalCost(totals) {
//totals += (totals * document.querySelector('input[id="PMODEL"]').value);
document.getElementById("amount").value = totals;
}

<fieldset id="MNDLS">
<legend>Noodles</legend>
<input type="checkbox" name="NDLS" id="PNDLS" value="0.5" onclick="pmodel()">
<label for="Model">Spaghetti</label><br>
<input type="checkbox" name="NDLS" id="PNDLS" value="0.5" onclick="pmodel()">
<label for="Model">Carbonara</label><br>
<input type="checkbox" name="NDLS" id="PNDLS" value="0.5" onclick="pmodel()">
<label for="Model">Lasagna</label><br>
<input type="checkbox" name="NDLS" id="PNDLS" value="0.5" onclick="pmodel()">
<label for="Model">Plain</label>
</fieldset>
<fieldset id="MMD" disabled>
<legend>Main Dish</legend>
<input type="radio" name="MD" value="50" onclick="total()">
<label>Chicken Wings ($50)</label><br>
<input type="radio" name="MD" value="55" onclick="total()">
<label>Chicken Breast ($55)</label><br>
<input type="radio" name="MD" value="60" onclick="total()">
<label>Pork Cutlets ($60)</label><br>
<input type="radio" name="MD" value="65" onclick="total()">
<label>Steak($65)</label>
</fieldset>
<fieldset id="ADDONS" disabled>
<legend>Sides</legend>
<input type="radio" name="ADDONS" value="1" onclick="total()">
<label>Nothing (100%)</label><br>
<input type="radio" name="ADDONS" value="1.5" onclick="total()">
<label>Softdrinks (150%)</label><br>
<input type="radio" name="ADDONS" value="2" onclick="total()">
<label>Softdrinks and Fries (200%)</label>
</fieldset>
<br>
<p><strong>Amount (US$)</strong>: <input type="text" name="amount" id="amount" value="" /></p>

Answer 1

首先，不要重复使用相同的ID，它们应该是唯一的。

相反，你可以用相同的类设置你的复选框(只是为了方便选择)，然后计算有多少个复选框被选中:

function pmodel() {
var count = 0;
var list=document.getElementsByClassName("PNDLS");
for (var i = 0; i < list.length; ++i) { if(list[i].checked) { count++; } } 
console.log(count);
}

<fieldset id="MNDLS">
<legend>Noodles</legend>
<input type="checkbox" name="NDLS" class="PNDLS" value="0.5" onclick="pmodel()">
<label for="Model">Spaghetti</label><br>
<input type="checkbox" name="NDLS" class="PNDLS" value="0.5" onclick="pmodel()">
<label for="Model">Carbonara</label><br>
<input type="checkbox" name="NDLS" class="PNDLS" value="0.5" onclick="pmodel()">
<label for="Model">Lasagna</label><br>
<input type="checkbox" name="NDLS" class="PNDLS" value="0.5" onclick="pmodel()">
<label for="Model">Plain</label>
</fieldset>
<fieldset id="MMD" disabled>
<legend>Main Dish</legend>
<input type="radio" name="MD" value="50" onclick="total()">
<label>Chicken Wings ($50)</label><br>
<input type="radio" name="MD" value="55" onclick="total()">
<label>Chicken Breast ($55)</label><br>
<input type="radio" name="MD" value="60" onclick="total()">
<label>Pork Cutlets ($60)</label><br>
<input type="radio" name="MD" value="65" onclick="total()">
<label>Steak($65)</label>
</fieldset>
<fieldset id="ADDONS" disabled>
<legend>Sides</legend>
<input type="radio" name="ADDONS" value="1" onclick="total()">
<label>Nothing (100%)</label><br>
<input type="radio" name="ADDONS" value="1.5" onclick="total()">
<label>Softdrinks (150%)</label><br>
<input type="radio" name="ADDONS" value="2" onclick="total()">
<label>Softdrinks and Fries (200%)</label>
</fieldset>
<br>
<p><strong>Amount (US$)</strong>: <input type="text" name="amount" id="amount" value="" /></p>