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How to set a span in JS instead of making a alert

Kind of a newbie to this but I have followed a totorial on a memory game as an attempt to understand the syntax of JS but am stuck on making the round result print in a instead of showing up as a alert
here is a codepen here.
how can I print round in a <span> <!-- result here--> </span> rather than like this alert("result")
How can I make it set to a span instead of being an alert?

Browsers parse HTML into a tree of objects called Document Object Model (DOM). Using JavaScript you can query the DOM to get individual nodes, and then change them.
To get your span, you would typically use document.getElementById or document.querySelector (there are other functions that can fetch collections of related nodes, like document.getElementsByClassName or document.querySelectorAll). The former identify nodes by the property named in the method name (ID, or class name, respectively); the latter ones use CSS selectors. (All of the getElement... functions can be replicated using the newer querySelector and querySelectorAll interface, though you have to know how to use CSS selectors. I almost never use getElement... functions any more.) There are also functions that use XPath, though this is a bit more advanced subject.
Once you have the node, you can change its content using e.g. .textContent or .innerHTML properties, the former being for plain text, the latter for HTML.
For example, if this is the only span on the page, this suffices:
document.querySelector('span').textContent = "Result";
<span></span>
If on the other hand you have more of them, you would need some way to target the correct one. I will also demonstrate how you can style it using HTML:
const node = document.querySelector('#result_goes_here');
node.innerHTML = "<strong>Result</strong> in bold!";
<span id="result_goes_here"></span>

If you are trying to add the result inside the HTML SPAN and not in the alert box. You can do it something like this:
document.getElementById("span_ID").innerHTML = the_variable_result_here;
Hope that helps!

How can I add a disable class to a single select, not all of that I have

I want to put a disabled class into my select, but when I do this:
$("input").attr("disabled",true);
//I tried to to this but it didn't work too:
$("#myId").attr("disabled",true);
It disable all of my selects and not one.
How can I disable only "myId"?

Without seeing your HTML (which at the time of writing has not been supplied) it's very difficult for us to tell you why it's not working.
However, if $("#myId").attr("disabled",true); isn't working, then it suggests to me that you do not have an element in your HTML with id='myId'.
Things to check in the rendered HTML (as seen by the browser, not your code)...
Is there an element with an id of myId
Is the id exactly myId, and not myID for instance (as the case is important)
Are you using something like ASP.Net where naming containers could be changing the id of the rendered control to something like ctl00_myId
Do you have 2 elements with an id of myId... in which case, this is invalid HTML, as each element must have a unique id, and would result in jQuery only setting the disabled on the first item

It disables them all because $("input").attr("disabled",true); adds the attribute disabled to all input elements. Without seeing your HTML it's hard to tell what the reason is for it not disabling when you try using #myId
Here are some mistakes I've made in the past for similar problems:
1) I did not actually have the id on the element that I thought I had. Whether it was a misspelling, or capitalization difference, or underscore vs dash...the point is the id I was trying to reference on the page simply did not match the one I was looking for with jQuery
2) I referenced it as an id but really it was a class or vice versa. . for classes, and # for id's is second nature, but sometimes if you're tired or exhausted you can very easily make that mistake
3) I had given an id that existed in multiple elements. id is supposed to be unique by convention. Duplicate id's will produce unexpected behavior
Hopefully one of these simple reasons is the cause for your issue and you can quickly resolve it. Maybe take a 30 minute break and come back to it.

Why does the jquery selector ("id,id") selects all elements with duplicate IDs

I came across some year old code written by a good developer (yes, I knew him personally) to access all elements having the same id.
$("#choice,#choice")
It returns all elements having the id. But if we use the below
$("#choice")
It returns only the first match, as expected.
After searching for some time, I'm unable to figure out any official links pointing to his technique, as to how it selected all elements with duplicate id.
Can anyone please explain how is this working ?
UPDATE
Please see the question is not about what alternative to use. I'm aware of classSelectors and attributeSelectors and know having duplicate IDs is not recommended, but sometimes you just have to live with years old code the way it is (if you know what I mean).
http://jsbin.com/zodeyexigo/1/edit?html,js,output

If you look at the code of sizzle.js that jQuery uses for selecting elements based on selector you will understand why this happens. It uses following regex to match simple ID, TAG or class selector:
// Easily-parseable/retrievable ID or TAG or CLASS selectors
rquickExpr = /^(?:#([\w-]+)|(\w+)|\.([\w-]+))$/,
but as the selector in question is $("#ID,#ID") it does not match with the selector and uses querySelectorAll (line no 270 in ref link), which replaces selector to "[id='" + nid + "'] " (line no 297 in ref link) which selects all the elements with matching ID.
However, I agree with the other people in this thread, that it is not good idea to have same ID for multiple elements.

Having 2 elements with the same ID is not valid html according to the W3C specification.
When your CSS selector only has an ID selector (and is not used on a specific context), jQuery uses the native document.getElementById method, which returns only the first element with that ID.
However, in the other two instances, jQuery relies on the Sizzle selector engine (or querySelectorAll, if available), which apparently selects both elements. Results may vary on a per browser basis.
However, you should never have two elements on the same page with the same ID. If you need it for your CSS, use a class instead.
If you absolutely must select by duplicate ID, use an attribute selector:
$('[id="a"]');
Take a look at the fiddle: http://jsfiddle.net/P2j3f/2/
Note: if possible, you should qualify that selector with a tag selector, like this:
$('span[id="a"]');

Having duplicated id on the page making your html not valid . ID is unique identifier for one element on the page (spec). Using classes, that are classify similar elements that's your case and $('.choice') will return set of elements

So in JS Fiddle i have shown an example of what jQuery is doing.
https://jsfiddle.net/akp3a7La/
When you have a
$('#choice,#choice');
It is actually getting all the instances of the objects #choice twice, and then filtering out any duplicates.
in my example i show you how it does that also when you have something like this
$("#choice,li");
Where items are actually your #choice items.
In the Jquery Documentation
https://api.jquery.com/multiple-selector/
it talks about multiple Selectors, which is what i think is happening here, your developer friend is selecting the same ID twice, and it would be returning it twice. as you can only have one input with the same ID once on a page (good html syntax)

How to use common js function for two divs containig elements of identical ids?

I have common jQuery function and two div tags. Both div tags have different names but both containing elements of identical ids now i want to use this common Jquery function for them both?
I have implemented common function but it's not working for both.
Here's link to my jsfiddle -jsfiddle.net/xS7zF/1/
In my jsfiddle there are two div tags namely example1 and example2 and both tags have elements of identical ids. Function is working fine for first div but not for second.
please help me to sort out this.

Yeah, under the hood, jQuery selection on an ID will use the Document.GetElementById() function implemented by the browser, which is really fast, but (i guess depending on the browser) will stop after it finds the first element, since ID's should be unique and no further searching is needed after the first one is found.
For instance, rename the divs with id="eb" to class="eb" and you can still target specific elements using $("#example1 .eb") and $("#example2 .eb")
UPDATE:
Using your new Fiddle I created this: http://jsfiddle.net/xS7zF/5/
I cleaned up a lot of code and hopefully you can see what I have done. I changed all elements that appear twice from id to class. Now, when you attach an event to an element using $(".classname").click(), it attaches to all the elements. In the handler function where you set HTML and do your show()/hide(), you don't target a specific element using it's ID, but you find it relative to the element that does the event. You can do this using parent(), parentsUntil(), next(), find(), etc. Check jQuery docs for all possibilities. So for instance, the change-handler attaches to all inputs with name=Assets. But instead of doing $("#b1").show(), I go to the parent of the specific input that fires using $(this).parent(). Then I find the element with a class=".b1", which it will only find the one that is next to this specific input and I set the HTML to just that element.
Since there is another input, the same actions happen when THAT input changes, but instead it finds IT's parent, and finds the element with class=".b1" that is next to IT. So both divs with input are contained since they act on elements relative to itself and not across the document.
For extra fun and to show you how flexible this way of programming is, here is a fiddle with the Javascript-code unchanged, but with the exact same question-div copied 8 times. No matter how many times you repeat this, the same code will act on as many divs as you create since everything works relative. http://jsfiddle.net/xS7zF/7/
Hopefully this helps, the rest is up to you!

ID's must be unique, you should not repeat them. You could replace id with class and in the jQuery function do (".ub").each() or manually referencing the object using eq(x). e.g. (".ub").eq(1).

You shouldn't assign same id's to different elements.
You CAN but you SHOULDN'T. Instead of giving the same id, use class

IDs must be unique, try fix this, change to classes.
You can try something like this:
$("div div:first-child")
instead of
$("#eb")
But depends of the rest of your page code. So, change to classes first and use
$(".eb")

when jQuery / javascript find the first ID it would ignore the rest, please read more about it
http://www.w3schools.com/tags/att_global_id.asp

Will jQuery search for the ID before filtering other parameters in the selector?

This question is related to performance.
If I use a selector like the following
$('#myID a') // Does this find #myID and filter by a?
Or should I write the statement like this?
$('#myID').find('a')
I'm not sure if jQuery is smart enough to execute this statement using the ID first or if it operates exactly like CSS and reads right to left. It's not such a big deal using tags but when you run something like
$('#myID .myClass')
It makes a HUGE difference in performance.

From a NetTuts article: http://net.tutsplus.com/tutorials/javascript-ajax/quick-tip-think-right-to-left-with-jquery/
As an example, if Sizzle comes across a selector like $('#box p'),
it’s true that it works right-to-left, but there’s also a quick regex
optimization that will first determine whether the first section of
the selector is an id. If so, it’ll use that as the context, when
searching for the paragraph tags.
Relevant comment from SizzleJS:
// Take a shortcut and set the context if the root selector is an ID
// (but not if it'll be faster if the inner selector is an ID)

When an Id is in the selector. jQuery will first execute document.getElementById then begin filtering for child elements.
basically this is why it is never a great idea to use just attribute or class selectors $('.someclass') or $('[name=myname]') without being more specific. Because it causes the code to traverse the DOM and look at every element to find that class.
By just adding a tagname to the same selector $('div.someclass') or $('div.[name=myname]') you improve efficiency becuase it will first run. document.getElementsByTagName narrowing the number of elements to search.