我在javascript中使用数组函数时遇到问题

Question

I made this simple shopping cart where you select quantity from a dropwdown list and these numbers get added and you get a total number for all the products and a total number for the product itself.

But i want it write the quantity with price and the name and write it in a div placed on the site so that it is easy for the user to see that he added a product. I made the calculating part by adding the products one by one, as i did not array them. But for this next part i just didn't find a way that suited my needs. This is just from my test page , so i only have a few values , but in the other page i have over 70 listed just like these:

<div id="radioAlert">
<script type="text/javascript">
//calculator
function updatesum() {
document.form.sum.value =
(document.form.sum0.value -0) *99 +
(document.form.sum1.value -0) *99 +
(document.form.sum2.value -0) *99;

document.form.smu.value =
(document.form.prod0.value -0)*99  +
(document.form.prod1.value -0) *99 +
(document.form.prod2.value -0) *99 +
(document.form.prod3.value -0) *99 +
(document.form.prod4.value -0) *99;
document.form.totalsum.value =
(document.form.sum.value -0) +
(document.form.smu.value -0); //not a typo i was just lazy with the name

//arrays

//This one i did not get to work.
var myArray = newArray();
myArray[0]=document.form.sum2.value;
myArray[1]=document.form.prod0.value;
myArray[2]=document.form.prod1.value;
myArray[3]=document.form.prod2.value;
myArray[4]=document.form.prod3.value;
myArray[5]=document.form.prod4.value;

for (var i = 0; i < myArray.length; i++) {
        alert(myArray[i]);
}


//this part works but i want it to add its value only once and then replace its value if its updated again, if its 0 i want it to be completely removed.

var prod1 = document.form.sum2.value;
var prod2 = document.form.sum1.value;

var radioAlert = document.getElementById("radioAlert");
var radioAlert2 = document.getElementById("radioAlert"); 

if  (document.form.sum2.value>0) {
//document.write("pilotjakke pelsforet small  " +   prod1 + "  stk");
radioAlert.innerHTML += ("pilotjakke pelsforet small  " +   prod1 + "  stk");
alert("pilotjakke pelsforet medium  " +   prod1 + "  stk");
}

if  (document.form.sum1.value>0) {
//document.write("pilotjakke pelsforet small  " +   prod1 + "  stk");
radioAlert2.innerHTML += ("pilotjakke pelsforet medium  " +   prod2 + "  stk");

}
}
</script>
</div>

Answer 1

There is no newArray function in JavaScript by default.

Change

var myArray = newArray();

to

var myArray = [];

or

var myArray = new Array();
// Note space ---^

The form using [] is generally preferred. In addition to being more concise, it's not susceptible to someone redefining the Array constructor function.

Note that you can initialize the array with the elements as well if you like:

var myArray = [
    document.form.sum2.value,
    document.form.prod0.value,
    document.form.prod1.value,
    document.form.prod2.value,
    document.form.prod3.value,
    document.form.prod4.value
];