How do I activate a javascript button as if a user clicked it?

Question

How do I activate a javascript button as if a user clicked it? Could I run javascript code to activate the button? (supposing I did not already know the code in the button, and I am on a random website where I can not change existing code)

<!DOCTYPE html>
<html>
  <body>
    <form action="aaa.php">
      <input type="text" />
      <input id="button" type="submit" />
    </form>
    <script>
      var btn = document.getElementById("button");
      //is there anything like: btn.click?
    </script>
  </body>
</html>

The syntax of the inline handler is invalid. If that's really the HTML markup you have, you can't run it as-is - it needs to be fixed first. But even still, [don't use inline handlers](https://stackoverflow.com/a/59539045), they have a demented scope chain, require global pollution, and have quote escaping issues. Use `addEventListener` instead — CertainPerformance, Apr 01 '20 at 20:14
@RobertoCaboni While I agree that one should not rely on automatic semicolon insertion, the fact that it's not added here is not an error, nor related to the question or answer. — Scott Marcus, Apr 01 '20 at 20:28

score 2 · Accepted Answer · answered Apr 01 '20 at 20:27

<!DOCTYPE html>
<html>
  <button id="button"onclick="myFunction()">b</button>
  <!--creates the button-->
  <script>
    var btn = document.getElementById("button");
    btn.click();
    
    function myFunction(){
       alert('working');
       }
  </script>
</html>

score -1 · Answer 2 · answered Apr 01 '20 at 20:22

-1

Here's one way you can handle it, call a specific function from your onClick

<!DOCTYPE html>
<html>
  <button id="button" onclick="clickButton()">b</button>
  <!--creates the button-->
  <script>
    function clickButton() {
       alert("hello!");
    }

  </script>
</html>

To answer your question more directly, this is one way you can do it

document.getElementById('button').onclick=function(){/* some code */}

answered Apr 01 '20 at 20:22

DSmith

9
2

I don't think you read/understood the question. You didn't actually answer what was being asked. – Scott Marcus Apr 01 '20 at 20:31

score -1 · Answer 3 · answered Apr 01 '20 at 20:26

-1

As mentioned, You can separate out HTML and javascript.

Sample.

<!DOCTYPE html>
<html>

<body>
    <button id="button">Click Here</button>
    <button onclick="onClickBtn(this)">Click Here 2</button>
    <!--creates the button-->
    <script>
        var btn = document.getElementById("button");
        btn.addEventListener("click", (event) => {
            alert("Hi")
        })
        function onClickBtn(event) {
            alert("Btn 2")
        }
    </script>
</body>
</html>

answered Apr 01 '20 at 20:26

xdeepakv

7,835
2
22
32

You've re-written the OPs code nicely, but you didn't actually answer the question. – Scott Marcus Apr 01 '20 at 20:30
What is the answer than ? – xdeepakv Apr 01 '20 at 20:35
Is there any code language other than English ? @ScottMarcus – xdeepakv Apr 01 '20 at 20:36
The question wasn't asking about how to set up event listeners. It was asking how to automate the `click` event. I've posted the one line answer in the comment below the question. – Scott Marcus Apr 01 '20 at 20:37
I think u only understand, rest of the others are equally didn't get the CODE WORD. The word activates me to enable, He didn't ask how to trigger. – xdeepakv Apr 01 '20 at 20:39
I think it's very clear. He said "as if a user clicked it", which is about as clear as can be. Also, @DCR understood and posted a correct answer. – Scott Marcus Apr 01 '20 at 20:41
yes after reading our count and 30 min later after the post. :D – xdeepakv Apr 01 '20 at 20:42
He actually posted his answer 1 minute before you did. – Scott Marcus Apr 01 '20 at 20:46

How do I activate a javascript button as if a user clicked it?

3 Answers3