Get window width depending on the browser with JavaScript

scripts.js

if ( getWidth() >= 992 ) {
 // do something
}

/* Get window width depending on the browser with JavaScript */
function getWidth() {
    if (this.innerWidth) {
        return this.innerWidth;
    }

    if (document.documentElement && document.documentElement.clientWidth) {
        return document.documentElement.clientWidth;
    }

    if (document.body) {
        return document.body.clientWidth;
    }
}