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Why is the following way to assign a value to a JSON array not working?

I have this code:
compareList[productName] = productID + ',' + productHref;
console.log(productName + ' ' + productID + ' ' + productHref + ' ' + compareList.length);
Which logs into this (I have removed the link):
Acer Iconia B1-790 [NT.LDFEE.002] 112576 link removed for confidentiality 0
As you can see, all three variables are valid strings, but the json object still fails to assign (compareList.length logs as 0). I've been thinking and thinking but I simply can't figure it out. Any help is appreciated.

Maybe this version of adding and checking array length can be useful to you?
var compareList=[]
var productName = {productID:'saban',productHref:'http://saulic.com'};
compareList.push(productName);
console.log(compareList.length);

Extract string html with regex on interval

There is a public website with this in the source:
</div><script type="text/rocketscript">
function calculateIndexIncome() {
var khs = $('#t9').val();
var btcusd = $('#t9_1').val();
var btckhs = $('#t9_2').val();
var dayprofitperkhs = 0.00000018188885404454654
var arr = btcusd.split(' ');
btcusd = arr[0];
var totalinvestmentusd = ((khs * btckhs) * btcusd).toFixed(2);
var totalinvestmentbtc = (khs * btckhs).toFixed(8);
var dailyincomebtc = (khs * dayprofitperkhs).toFixed(8);
var dailyincomeusd = ((khs * dayprofitperkhs) * btcusd).toFixed(2);
var monthlyincomebtc = (dailyincomebtc * 31).toFixed(8);
var monthlyincomeusd = (dailyincomeusd * 31).toFixed(2);
var breakevendays = (totalinvestmentusd / dailyincomeusd).toFixed(0);
var monthlypercentage = ((100 / breakevendays) * 30).toFixed(2);
$('#tl').html('Total KHS: ' + khs + '<br/>Total Investment: ' + totalinvestmentbtc + ' BTC ($' + totalinvestmentusd + ' USD)<br/><br/>Daily Income: ' + dailyincomebtc + ' BTC ($' + dailyincomeusd + ' USD)<br/>Monthly Income: ' + monthlyincomebtc + ' BTC ($' + monthlyincomeusd + ' USD)<br/><br/>Break Even In: ' + breakevendays + ' Days.<br/><br/>Monthly Rate: ' + monthlypercentage + '%');
}
I need to be able to extract two values: btckhs and dayprofitperkhs.
if I look at page source, dayprofitperkhs is different everytime I refresh.
Edit:
Jimmy Chandra came up with this bookmarklet:
javascript:
setInterval(logging,60000);
w1 = window.open("https://scrypt.cc/index.php");
function logging(){
console.log (w1.$('#t9_2').val());
var re=/var\s*dayprofitperkhs\s*=\s*([0-9\.]+)\s*/gi;
var matches=re.exec(document.body.innerHTML);
console.log(RegExp.$1);
w1.location.href = 'https://scrypt.cc/index.php';
}
This works ALMOST perfectly. it gets the dayprofitperkhs, but only on the first interval.
After that, the value is no longer updated, although t9_2 IS updated...
Anyone?

I don't know where that site is, so I am just running this against this SO question, but the following bookmarklet is getting me what I want...
As I mentioned in the comment, I use Regular Expression against the document body inner html and I am looking for dayprofitperkhs and capturing the numbers and decimal separator on the right side of the equal sign. Also trying to compensate for any extra spaces in between (\s*). RegExp.$1 gave me the number that I am looking for.
javascript:(function(){var re=/var\s*dayprofitperkhs\s*=\s*([0-9\.]+)\s*/gi;var matches=re.exec(document.body.innerHTML);console.log(RegExp.$1);}());
So your final bookmarklet should be something like:
javascript:
setInterval(logging,60000);
w1 = window.open("siteurl.com");
function logging(){
console.log (w1.$('#t9_2').val());
var re=/var\s*dayprofitperkhs\s*=\s*([0-9\.]+)\s*/gi;
var matches=re.exec(w1.document.body.innerHTML);
console.log(RegExp.$1);
w1.location.href = 'siteurl.com';
}

The variables in question are local variables within the calculateIndexIncome() function, so no, you can't access them from outside that function.
The reason the first one "works" is because you're not referring to the variable, but rather the value: $('#t9_2').val(). This is a jquery selector which finds the element with the ID t9_2 and grabs its value.

You cannot visit it because its a local variable, it only exists in calculateIndexIncome() function.
By the way, you needn't open a new window to visit the variables. You can use chrome dev tools to directly modify the javascript to print the values, or set a breakpoint to debug the code.
Here is a tutorial for chrome dev tools: https://www.codeschool.com/courses/discover-devtools

In Qualtrics surveys, how can you use JavaScript to dynamically set the range of a slider?

I was making a survey in Qualtrics, and needed to have my items show different values of the slider depending on a variable, in my case, the value from a loop and merge. That didn't seem like a thing that you could do with piped text, so I had to figure out how to do it in Javascript.
I'm just posting this as an opportunity to provide the answer I found on my own. As usual with Qualtrics, your mileage may vary, and this may need to be modified for your specific situation. In particular, the question IDs and postTags change depending on whether it is in a loop/merge, and perhaps on other factors.

Put the following code into the javascript section of the question:
// Set the slider range
// First define the function to do it
setSliderRange = function (theQuestionInfo, maxValue) {
var postTag = theQuestionInfo.postTag
var QID=theQuestionInfo.QuestionID
// QID should be like "QID421"
// but postTag might be something like "5_QID421" sometimes
// or, it might not exist, so play around a bit.
var sliderName='CS_' + postTag
window[sliderName].maxValue=maxValue
// now do the ticks. first get the number of ticks by counting the table that contains them
var numTicks = document.getElementsByClassName('LabelDescriptionsContainer')[0].colSpan
// do the ticks one at a time
for (var i=1; i<=numTicks; i++) {
var tickHeader='header~' + QID + '~G' + i
// the first item of the table contains the minimum value, and also the first tick.
// so we do some tricks to separate them out in that case.
var tickSpanArray = $(tickHeader).down("span.TickContainer").children
var tickSpanArrayLength=tickSpanArray.length
var lastTickIndex=tickSpanArrayLength - 1
var currentTickValue = tickSpanArray[lastTickIndex].innerHTML
currentTickValue=currentTickValue.replace(/^\s+|\s+$/g,'')
console.log('Tick value ' + i + ' is ' + currentTickValue)
// now get the new value for the tick
console.log('maxValue: ' + maxValue + ' numTicks: ' + numTicks + ' i: ' + i)
var newTickValue = maxValue * i / numTicks //the total number of ticks
tickSpanArray[lastTickIndex].innerHTML=newTickValue.toString()
console.log('Changed tick value to ' + newTickValue)
}
}
var currentQuestionInfo = this.getQuestionInfo()
var currentQuestionID = currentQuestionInfo.QuestionID
// Now call the function
setSliderRange(currentQuestionInfo, theMaxValueYouWant)
If you find my answers helpful, help raise my reputation enough to add "qualtrics" as a valid tag!! Or, if someone else with reputation over 1500 is willing to do it that would be very helpful!

Create variable from array keys in JavaScript

Is there a way to make a variable using an array value? For ex.
//Define all Notes in Sharps and Flats
var noteSharp = ["A","A#","B","C","C#","D","D#","E","F","F#","G","G#"];
var noteFlat = ["A","Bb","B","C","Db","D","Eb","E","F","Gb","G","Ab"];
//Make all Major Scales
for (var x=0; x<12; x++){
var noteSharp[x] + "Sharp" = noteSharp[x] + noteSharp[x+2] + noteSharp[x+4] + noteSharp[x+5] + noteSharp[x+7] + noteSharp[x+9] + noteSharp[x+11];
var noteFlat[x] + "Flat" = noteFlat[x] + noteFlat[x+2] + noteFlat[x+4] + noteFlat[x+5] + noteFlat[x+7] + noteFlat[x+9] + noteFlat[x+11];
}
If I do a console.log(CSharp) it says that CSharp is not defined.
In this example I am trying to define a total of 24 variables. Some variable name examples im expecting to get are ASharp , A#Sharp , BbFlat , DFlat. The CSharp and CFlat variable should both be "CDEFGAB"
If this is not possible is it because variables have to be defined before the javascript file is read by the browser at run-time for memory leak security.

If you want to make a global variable, attach it to window
window[variableNameHere] = itsValue;
In your case:
window[noteSharp[x] + "Sharp"] = noteSharp[x] + ...
But it's not good to pollute the global namespace. How about putting it in another namespace:
var sharps = {};
var flats = {};
sharps[noteSharp[x] + "Sharp"] = noteSharp[x]...
flats[noteFlat[x] + "Sharp"] = noteFlat[x]...
//access them
sharps.ASharp;
I quite can't figure out what your code does, but this solution should point you to the right direction.

try the following code
var noteSharp = ["A","B","C"];
for(i in noteSharp) {
window[noteSharp[i]] = 'value of '+noteSharp[i];
}
alert(A)
alert(B)
alert(C)
This is exactly what you want.
and rewriting it for your code
//Define all Notes in Sharps and Flats
var noteSharp = ["A","A#","B","C","C#","D","D#","E","F","F#","G","G#"];
var noteFlat = ["A","Bb","B","C","Db","D","Eb","E","F","Gb","G","Ab"];
//Make all Major Scales
for (var x=0; x<12; x++){
window[noteSharp[x] + "Sharp"] = noteSharp[x] + noteSharp[x+2] + noteSharp[x+4] + noteSharp[x+5] + noteSharp[x+7] + noteSharp[x+9] + noteSharp[x+11];
window[noteFlat[x] + "Flat"] = noteFlat[x] + noteFlat[x+2] + noteFlat[x+4] + noteFlat[x+5] + noteFlat[x+7] + noteFlat[x+9] + noteFlat[x+11];
}
alert(ASharp);
alert(AFlat);

As per my knowledge, in JavaScript there are 2 ways by which you can create dynamic variables:
eval Function
window object
eval:
var times = 1;
eval("var sum" + times + "=10;");
alert(sum1);
window object:
var times = 1;
window["sum" + times] = 10;
alert(window["sum1"]);

Change the end of your code to look like this:
for (var x=0; x<12; x++){
self[noteSharp[x] + "Sharp"] = noteSharp[x] + noteSharp[x+2] + noteSharp[x+4] + noteSharp[x+5] + noteSharp[x+7] + noteSharp[x+9] + noteSharp[x+11];
self[noteFlat[x] + "Flat"] = noteFlat[x] + noteFlat[x+2] + noteFlat[x+4] + noteFlat[x+5] + noteFlat[x+7] + noteFlat[x+9] + noteFlat[x+11];
}
As a result, you will have global variables with variable names like you want, such as CSharp, which would equal "CDEFGAB"--however, complicated variable names like A#Sharp cannot be written outright as variables, but can still be accessed by using subscript notation, like this self["A#Sharp"] (or window["A#Sharp"] in most cases, although it has traditionally been better style to use self rather than window to refer to the most local window object connected with a script instance).
The other answer looks like it has been finished out by the time I finished typing mine, and it looks good, too.

If this is not possible
It isn't for local variables without the use of eval.
is it because variables have to be defined before the javascript file is read by the browser at run-time for memory leak security.
No. It's not possible because ECMA-262 specifies that the only way to declare a variable is by a variable declaration statement, which is of the form:
var *identifier* [optional initialiser]
where identifier is a valid identifier, which can't be an expression like:
var 'foo' + 'bar';
The rest of the question has been covered in other answers.

How can I get these array values to all print into an html form?

I have a small piece of code that generates an array with values based on a triangle. I will post the array below.
var endwallPanelLengths = [totalHeightInches];
var i = 0;
while (endwallPanelLengths[i] > eaveInches)
{
endwallPanelLengths.push(endwallPanelLengths[i] - peakHeightDecrease);
document.getElementById("test83").value="4 - " + endwallPanelLengths[i];
i++;
}
This array will have anywhere between 2 to 100 indexes. I want the code to write all of the values separated by breaks into a <textarea> with the id="test83".
If I run the code as it is set up above it will only write the value in array [1] not [0] or any of the others. How can I get it to write all of them so that they come out looking like this...
4 - 140 this is the value of array position [0]
4 - 126
4 - 116 and so on?

You keep replacing the value
document.getElementById("test83").value="4 - " + endwallPanelLengths[i];
You would need to append to the value
document.getElementById("test83").value += "4 - " + endwallPanelLengths[i] + "\n";
better yet, build up the values and set the value once
var endwallPanelLengths = [totalHeightInches],
i = 0,
output = [];
while (endwallPanelLengths[i] > eaveInches)
{
endwallPanelLengths.push(endwallPanelLengths[i] - peakHeightDecrease);
output.push("4 - " + endwallPanelLengths[i]);
i++;
}
document.getElementById("test83").value = output.join("\n");

If I'm understanding you correctly, that you want the array displayed with one item per line in your textarea, then you should be able to ditch your loop completely, and just do it in one shot.
document.getElementById("test83").value = endwallPanelLengths.join('\n');
Although it also looks like you're prepending '4 -' to each value. If that's the case, then you could just add one extra step to get those fours added:
var arr = endwallPanelLengths.map(function(item){ return '4 - ' + item; });
document.getElementById("test83").value = arr.join('\n');
Just be sure to grab the shim for Array.prototype.map from here if you need to support IE8

HTML:
<div id="holder"></div>
JavaScript:
var endwallPanelLengths = [totalHeightInches];
var i = 0;
var holder = document.getElementById("holder");
while (endwallPanelLengths[i] > eaveInches)
{
endwallPanelLengths.push(endwallPanelLengths[i] - peakHeightDecrease);
var e = document.createElement('div');
e.innerHTML = "4 - " + endwallPanelLengths[i] + "<br />";
holder.appendChild(e.firstChild);
i++;
}
Hopefully that does for you what you want. In your example, in your loop, you're setting the newest value to the same element, thus overwriting any previous values.