const flip = (max) => {
    if (Math.floor(Math.random() * max) == 1) {
        return "heads"
    } else 
    return "tails";
}
//console.log(flip(1));

let quater = document.getElementById("coin");

quater.addEventListener("click", flip);

<div class="random">
  <button id ="coin" onclick="">flip</button>
  
  
</div>

<iframe name="sif1" sandbox="allow-forms allow-modals allow-scripts" frameborder="0"></iframe>

context :Adding an event listener to connect the button to the function

CodePudding user response：

If you are looking for code that executes a function if a specific element is clicked the following snippet should work (replacing relevant ids and functions).

document.getElementById("elementIdHere").addEventListener("click", runThisFunction);

CodePudding user response：

The callback (flip) will receive a mouse click event as the first parameter. In your case, it would be the num param which you use as a number thus making the code not work. You can do this instead

quater.addEventListener("click", event => {
  flip(10);
});