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Question

Loop wont add up a running total of form values.

Answer 1

A:

In this code, you never do anything with total, it's always 0.

function getval2(){
var total=0;
var checkboxes = document.forms["orderform"].amen;
for (var i = 0; i < checkboxes.length; i++) {
checkboxes[i].value += total;
}
return total;
}

Also, one tip that might help you in debugging these types of things (and making your code better in general) is to try using indentation.

dcp 2010-09-01 15:44:55

Thanks for the answer. It was indented but the formatting was lost. Anyway, you say I am doing nothing with the total variable, so what is the script doing instead. Especially on this line:checkboxes[i].value += total; If it helps any my intention with this code was to loop through and get the value of the selected radio and checkbox.

Isaac 2010-09-01 17:53:32

@Isaac - You declare and initialize total to 0. Then you loop over checkboxes and add total to checkboxes[i].value. But total is always 0 since you never change it's value anywhere. So what exactly is your intention here? If you are trying to get the checkbox's value, then why are you adding total to it? Just get the value.

dcp 2010-09-01 18:36:56

My thinking was that since I had two sets of radio boxes I would loop through all of them and since both sets had differentnamesthat I would just add them(the respective values) together. Total acts as a placeholder for all the selected values in the form.

Isaac 2010-09-01 18:52:27

Answer 2

+2 A:

The code has multiple issues.

Here's a working jsFiddle example you can play with.

There's 4 big problems that stop your code from working:

In your if loops, when you want to add to the total you write:
```
options[i].value += total;
```
This will act upon options[i].value. You want to change total, so you should write
```
total += parseFloat(options[i].value);
```

In getval() you return from inside the for loop like this:

function getval(){
    var options = document.forms["orderform"].manual;
    var optionslength = options.length;
    var total = 0;
    for (var i = 0; i &lt; optionslength; i++) {
        if (options[i].checked) {
            options[i].value += total;
        }
        return total; // <=======   THIS IS STILL INSIDE THE FOR LOOP!!!!!!!!
    }
}

You want total after all you calculations, so like this:

function getval(){
    var options = document.forms["orderform"].manual;
    var optionslength = options.length;
    var total = 0;
    for (var i = 0; i &lt; optionslength; i++) {
        if (options[i].checked) {
            total += parseFloat(options[i].value);
        }            
    }
    return total; // <===== ALL CALCULATIONS ARE COMPLETED, SO WE CAN RETURN.
}

Finally in getval2(), you forgot to check whether the boxes are checked before adding them to the total. So you always get the same total. You check whether the boxes checked in getval(). Use the same method in getval2().
When you get options[i].value you are getting a string. You should convert these to numbers before adding them to total. You only convert to numbers after the totals are returned, by then all sorts of funny concatenations have happened. Look at where I use parseFloat() in the snippets above and in the jsFiddle.

Peter Ajtai 2010-09-02 00:34:49

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Loop wont add up a running total of form values.

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