JSFiddle - React, Tailwind, and code Playground

HTML

<div id="click-test-1"></div>
<div id="click-test-2"></div>
<div id="click-test-3"></div>
<div id="click-test-4"></div>
<div id="click-test-5"></div>
<input type="button" value="test" onclick="getDivs()"/>

JavaScript

function getDivs() {

    var children = document.body.getElementsByTagName('div');
    var elements = [],
        child;
    for (var i = 0, length = children.length; i < length; i++) {
        child = children[i];
        if (child.id.indexOf("click-test") == 0) elements.push(child);
    }
    
    console.log(children.length);
    
}