Identifier 'x' has already been declared Cannot read property 'addEventListener' of null

Question

A simple form to submit search result

<form>

    <label for="searchTerm">Search Term</label>
    <input type="text" id="searchTerm" name="searchTerm">
    <button type="submit">Search</button>

</form>

in main.js

const form = document.querySelector("form");
const input = document.querySelector("input");
//adding listener to form 
form.addEventListener("submit", formSubmitted);

I am getting two errors ?

Uncaught TypeError: Cannot read property 'addEventListener' of null

Uncaught SyntaxError: Identifier 'form' has already been declared

First issue might be because you are capturing form before the dom is ready. Second one because you already have a variable/constant declared. With the code you provided there is nothing wrong, we need more context — A. Llorente, Jun 13 '18 at 07:52

Peter B · Answer 1 · 2018-06-13T07:58:13.237

With document.querySelector() it is best to use an element id #someId or a class specifier .someClass, or even a combination of both. See MDN Reference.

As for why it complains about form: it apparantly is defined already elsewhere, just pick a more unique name, or wrap your code in a function and then call that function.

const form = document.querySelector("#theForm");
console.log("form: " + form);

const input = document.querySelector("#searchTerm");
form.addEventListener("submit", formSubmitted);

function formSubmitted() {
  //...
}

<form id="theForm">
  <label for="searchTerm">Search Term</label>
  <input type="text" id="searchTerm" name="searchTerm">
  <button type="submit">Search</button>
</form>

thanks peter but the error was something else – Sanjay Jun 13 '18 at 07:55 — Sanjay, Jun 13 '18 at 07:55

score 0 · Answer 2 · answered Jun 13 '18 at 07:54

0

Silly mistake : i had imported same main file twice in same file

<script src="main.js"></script>

answered Jun 13 '18 at 07:54

Sanjay

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Identifier 'x' has already been declared Cannot read property 'addEventListener' of null

2 Answers2