JavaScript - Dynamic Array and Looping

Question

Imagine you have a product page. On this page there are two select inputs with options in them.

There is one for Size and Colour. This can change depending on the product, e.g. a curtain might have a size, length and colour (three select menus).

The array is created dynamically (based on each select menu and its options):

var dynamicArr = [],
    i,
    j,
    opt,
    $('.select');

for (i = 0; i < select.length; i += 1) {

    opt = select.eq(i).find('option');

    if (dynamicArr[i] === undefined) {
        dynamicArr[i] = [];
    }

    for (j = 0; j < opt.length; j += 1) {
        dynamicArr[i].push(opt.eq(j));
    }

}

Imagine the page had a size and colour drop-down. The above would create an array like this:

dynamicArr = [['size'], ['color']]

I want to loop through each of these separately (in order to get individual values and compare them).

My problem starts here. A dynamic array might have a length of 1, 2, 3, 4, 5, 6 (depending on the select options on the page). I therefore can't do this as there won't always be two selects

for (i = 0; i < dynamicArr[0].length; i += 1) { 
}
for (i = 0; i < dynamicArr[1].length; i += 1) { 
}

How would I go about finding out the length and looping individually like the above e.g. if there are three selects, it will automatically know there are this many and loop through them like above.

If you are still confused, let me know.

Thanks.

Amit Joki · Accepted Answer · 2014-10-29 16:42:29Z

1

You can always use Array.forEach

dynamicArr.forEach(function(el){
   console.log(el);
});

answered Oct 29, 2014 at 16:42

Amit Joki

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1 Comment

Paddy Over a year ago

Would that give me both values at the same time so I can access both of them and compare? If so, could you give me an example?

Joe · Accepted Answer · 2014-10-29 16:46:56Z

0

I hope I didn't get you wrong, but here's a solution:

for(i = 0; i < dynamicArr.length; i++) {
    for(j = 0; j < dynamicArr[i].length; j++) {
        // do something here..
    }
}

answered Oct 29, 2014 at 16:46

Joe

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1 Comment

Paddy Over a year ago

Hey, Thanks for the response. I have already tried this method. That allows me to loop through the inner arrays :). I need to get them separate so that I can compare them.

Coder55 · Accepted Answer · 2014-10-29 16:58:01Z

0

you should try something like this: dyn.forEach(function(el){//dyn is the dynamic array console.log(el); //logs to console });

answered Oct 29, 2014 at 16:58

Coder55

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1 Comment

Paddy Over a year ago

Can you expand on this and show me how I can compare both returned values. I can see how it works in the console, but don't know how I would use it just yet.

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