How to fix NaN in javascript

Asked May 04 '21 at 16:50

Active May 04 '21 at 16:56

Viewed 9 times

-1

I want to create a program that gives you random equations and you can decide what the maximum numbers are. When I for example enter 5 and then click ok. it gives me NaN+NaN. I think this means not-a-number. I have tried converting it to a number with number(). BUt that gave me the same output. How can I fix this?

function bee() {
  var text1 = document.getElementById('number').value;
}

function button() {
  var rand1 = Math.floor(Math.random() * text1);
  var rand2 = Math.floor(Math.random() * text1);
  var html = "<input type='text' id='id'> <button onclick=' check() '> check </button>" + Number(rand2) + '+' + Number(rand1);
  document.getElementById('div').innerHTML = html;
  var text1 = document.getElementById('number').value;
  var answer1 = rand1 + '+' + rand2;
  document.write(html)
  return rand1 + rand2;
}

function check() {
  var text11 = document.getElementById('id').value;
  if (answer == text11) {
    document.write('correct!')
  }
}
bee()

<p>maximum number:<input type="text" id="number"></p>
<button onclick="button()"> ok </button>
<div id='div'>

edited May 04 '21 at 16:56

Barmar

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asked May 04 '21 at 16:50

red_panda

Your `var text1 =` is scoped to only inside the `bee` function. It's hoisted and `undefined` inside your `button` function, and your `var text1 =` inside the `button` function is after you try to access it. – CertainPerformance May 04 '21 at 16:53
`text1` is a local variable in `bee()`. It's not available in `button()`. – Barmar May 04 '21 at 16:53
How can I make it global? – red_panda May 04 '21 at 16:53
Declare it outside the functions. – Barmar May 04 '21 at 16:54
Another problem: you only call `bee()` when the page first loads, before the user has filled in the input. – Barmar May 04 '21 at 16:55
You don't need the function, get the value of the input inside `button()`. – Barmar May 04 '21 at 16:56
Okay I edited question @Barmar – red_panda May 04 '21 at 16:56
I rolled back the edit, since it changes the problem completely and the duplicate wouldn't apply. – Barmar May 04 '21 at 16:57
You also shouldn't use `document.write()` in code that runs after the page has loaded. – Barmar May 04 '21 at 16:58
See https://stackoverflow.com/questions/802854/why-is-document-write-considered-a-bad-practice – Barmar May 04 '21 at 16:58
I basically just deleted te bee() function – red_panda May 04 '21 at 16:59
`if (answer == text11)` you never defined `answer` – Barmar May 04 '21 at 16:59
I know what you did. That's a completely different question, with a different solution. – Barmar May 04 '21 at 16:59
In your modified question, `text1` is always an empty string, because you don't update it when the user fills in the input. – Barmar May 04 '21 at 17:01
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/231947/discussion-between-red-panda-and-barmar). – red_panda May 04 '21 at 17:01

How to fix NaN in javascript

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