Count Number of DIVs

/* Write a JavaScript function countDivs(html) to count the number of all DIVs in given HTML fragment
 passed as string. Write a JS program countOfDivs.js that invokes your function and prints the output
 at the console. */

"use strict";

function countDivs(html) {
    var pattern = /<div[^<]*>/g;
    return html.match(pattern).length;
}

console.log(countDivs(
    '<!DOCTYPE html>' +
    '<html>' +
    '<head lang="en">' +
    '<meta charset="UTF-8">' +
    '<title>index</title>' +
    '<script src="/yourScript.js" defer></script>' +
    '</head>' +
    '<body>' +
    '<div id="outerDiv">' +
    '<div class="first">' +
    '<div><div>hello</div></div>' +
    '</div>' +
    '<div>hi<div></div></div>' +
    '<div>I am a div</div>' +
    '</div>' +
    '</body>' +
    '</html>'));