I want to handle multiple buttons. My aim is when a user will click on the first button then the first paragraph will be changed, again when a user will click on the second button then the second paragraph will be changed. I tried, but not working. Please check my code and give me a solution....
var len = document.querySelectorAll(".myButton").length
var plen = document.querySelectorAll(".myP").length
for (i = 0; i < len; i++) {
for (j = 0; j < plen; j++) {
document.querySelectorAll(".myButton")[i].addEventListener("click", function() {
if (document.querySelectorAll(".myButton")[i] == document.querySelectorAll(".myP")[j]) {
document.querySelectorAll(".myP")[j].innerHTML = document.querySelectorAll(".myButton")[i].innerHTML;
}
});
}
}<p class="myP">oke</p>
<p class="myP">oke</p>
<h1 class="pt-3 pb-3 pl-5 pr-5 bg-warning text-light btn mx-5 my-5">00</h1><br>
<hr style="background-color:red; width:50%">
<button class="btn bg-primary text-light mx-5 my-5 myButton">one</button>
<button class="btn bg-primary text-light mx-5 my-5 myButton">two</button>error:
5_eventListener.html:43 Uncaught TypeError: Cannot read properties of undefined (reading 'innerHTML')
at HTMLButtonElement.<anonymous> (5_eventListener.html:43:119)
Error line:
document.querySelectorAll(".myP")[j].innerHTML = document.querySelectorAll(".myButton")[i].innerHTML;
Your code needs closures to work and that is quite tricky
Instead delegate - here I delegate from document, but if the buttons have a wrapper, you can delegate from that
Much simpler. Also use data attributes to give a target to the buttons
document.addEventListener("click", function(e) {
const tgt = e.target;
if (!tgt.matches(".myButton")) return
document.getElementById(tgt.dataset.target).innerHTML = tgt.innerHTML;
}) <p class="myP" id="p1">oke</p>
<p class="myP" id="p2">oke</p>
<h1 class="pt-3 pb-3 pl-5 pr-5 bg-warning text-light btn mx-5 my-5">00</h1><br>
<hr style="background-color:red; width:50%">
<button class="btn bg-primary text-light mx-5 my-5 myButton" data-target="p1">one</button>
<button class="btn bg-primary text-light mx-5 my-5 myButton" data-target="p2">two</button>I dont understand why you will need such a thing - but, here go - a version real close to @mplungjan which is correct, i just don't think you should listen to a click on the entire document, also made it more readable for beginners i hope
Live example:
https://jsfiddle.net/dm3bwzgr/
<p id="p1">text 1</p>
<p id="p2">text 2</p>
<button class="btn" data-target="p1">Button 1</button>
<button class="btn" data-target="p2">Button 2</button>
<script>
// listen to click event on all buttons
document.querySelectorAll('.btn').forEach(function(btn) {
btn.addEventListener('click', function() {
var target = btn.dataset.target
var el = document.getElementById(target)
// apply button text to target element
el.innerHTML = btn.innerHTML;
});
});
</script>