give an onclick function to be executed to every element with a certain class

How would i go about making something like this - i have multiple elements with a certain class and i would like this to happen:

element1 - onclick fires someFunction(13);

element2 - onclick fires someFunction(27);

element3 - onclick fires someFunction(81);

i am loading these elements in dynamically so i can't put it manually into my js file. I also can't give them an onclick as i load them with php. I am looking for a purely js answer so please no jQuery.

The simplest way of doing this is giving the elements a data-attribute with the parameter for the function you want to run:

<div class="someclass" data-parameter="12">
<div class="someclass" data-parameter="13">
<div class="someclass" data-parameter="14">

and then run this:

function setMyHandler(){
   var elements = document.getElementsByClassName('someclass');
   for(var i = 0; i < elements.length; i++){
      elements[i].onclick = function(){ myFunction(this.data.parameter); };
   }
}

Here is a link for data attributes: data attributes

And here is a snipplet to see the simple version of it in action:

function setMyHandler(){
   var elements = document.getElementsByClassName('someclass');
   for(var i = 0; i < elements.length; i++){
      elements[i].onclick = function(){window.alert(this.dataset.somevalue);};
   }
}

setMyHandler();

body {
  display: flex;
  justify-content: center;
}

div.someclass {
  margin: 2%;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  cursor: pointer;
  background: #80bfff;
  box-shadow: 0px 2px 6px 0px rgba(0,0,0,0.7);
  transition: background 0.3s ease;
}

div.someclass:hover {
  background: #3399ff;
}

<div class="someclass" data-somevalue="13">  </div>

<div class="someclass" data-somevalue="14">  </div>

<div class="someclass" data-somevalue="15">  </div>