HTML/Javascript Button Click Counter

Don't use the word "click" as the function name. It's a reserved keyword in JavaScript. In the bellow code I’ve used "hello" function instead of "click"

<html>
<head>
    <title>Space Clicker</title>
</head>

<body>
    <script type="text/javascript">

    var clicks = 0;
    function hello() {
        clicks += 1;
        document.getElementById("clicks").innerHTML = clicks;
    };
    </script>
    <button type="button" onclick="hello()">Click me</button>
    <p>Clicks: <a id="clicks">0</a></p>

</body></html>

After looking at the code you're having typos, here is the updated code

var clicks = 0; // should be var not int
    function clickME() {
        clicks += 1;
        document.getElementById("clicks").innerHTML = clicks; //getElementById() not getElementByID() Which you corrected in edit
 }

Demo

Note: Don't use in-built handlers, as .click() is javascript function try giving different name like clickME()


Use var instead of int for your clicks variable generation and onClick instead of click as your function name:

var clicks = 0;

function onClick() {
  clicks += 1;
  document.getElementById("clicks").innerHTML = clicks;
};
<button type="button" onClick="onClick()">Click me</button>
<p>Clicks: <a id="clicks">0</a></p>

In JavaScript variables are declared with the var keyword. There are no tags like int, bool, string... to declare variables. You can get the type of a variable with 'typeof(yourvariable)', more support about this you find on Google.

And the name 'click' is reserved by JavaScript for function names so you have to use something else.