Cannot get inner HTML from an element

Question

Just wondering why do I get an output of NaN not 100 using this code (the class was changed to time recur by the way, it's not on the screenshot but keep it in mind):

z = +(document.getElementsByClassName("time recur").innerHTML)

View the docs on `getElementsByClassName` it doesn't return a single element — scrappedcola, Jun 15 '16 at 20:11
... Is there a reason you posted an image of HTML rather than just, you know, the HTML? It wouldn't even take that much time to just type that out. — Heretic Monkey, Jun 15 '16 at 20:11
you could use z = +(document.querySelector(".time.recur").innerHTML); — Brajendra Swain, Jun 15 '16 at 20:13
@neocorp: adding + will covert it to number : alternative for parseInt — Brajendra Swain, Jun 15 '16 at 20:15
Clarification to some of the below answers: `getElementsByClassName` does _not_ return an array, at least not one with the `Array` prototype. It returns an [`HTMLCollection`](https://developer.mozilla.org/en-US/docs/Web/API/HTMLCollection), so don’t be surprised if `Array` prototype methods don’t work on your element list. — Sebastian Simon, Jun 15 '16 at 20:38
Possible duplicate of [What does getElementsByClassName return?](http://stackoverflow.com/questions/10693845/what-does-getelementsbyclassname-return) — Sebastian Simon, Jun 15 '16 at 20:47

score 1 · Accepted Answer · answered Jun 15 '16 at 20:12

1

getElementsByClassName returns an array.

z = +(document.getElementsByClassName("time recur")[0].innerHTML)

By the way,I can't see the class 'recur' in your element. You might need to ignore it in JavaScript

answered Jun 15 '16 at 20:12

Mojtaba

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score 0 · Answer 2 · answered Jun 15 '16 at 20:12

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Because getElementsByClassName returns array.

z = +(document.getElementsByClassName("time recur")[0].innerHTML)

answered Jun 15 '16 at 20:12

mokarakaya

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My answer was the same – Mojtaba Jun 15 '16 at 20:15
:) yes, same answers at the same time. – mokarakaya Jun 15 '16 at 20:15

score 0 · Answer 3 · answered Jun 15 '16 at 20:14

You have to do something like this:

z = + parseInt((document.getElementsByClassName("time recur")[0].innerHTML));

When you select element by class, you might get more than one matched element, so you have to select first with index 0. And then, you have to convert it to Integer in order to use in math operation. Hope this helps.

Cannot get inner HTML from an element

3 Answers3