Wanna FAFO what a jawn is? Use this javascript function!

whatIsThisJawn.js

/**
 * Wanna FAFO what a jawn is? Use this function!
 * @param {*} jawn The jawn. Any jawn.
 * @returns {string} What the jawn is...
 */
function whatIsThisJawn(jawn) {
    let answer = 'Yo this jawn is';

    if (jawn === undefined || jawn === null) {
        return `${answer} ${jawn}`;
    }

    return `${answer} an instance of ${jawn.constructor && jawn.constructor.name}`;
}

whatIsThisJawn(undefined);
//=> 'Yo this jawn is undefined'
whatIsThisJawn(null);
//=> 'Yo this jawn is null'
whatIsThisJawn(1);
//=> 'Yo this jawn is an instance of Number'
whatIsThisJawn('asdf');
//=> 'Yo this jawn is an instance of String'
whatIsThisJawn({});
//=> 'Yo this jawn is an instance of Object'
whatIsThisJawn([]);
//=> 'Yo this jawn is an instance of Array'
whatIsThisJawn(new Date());
//=> 'Yo this jawn is an instance of Date'
whatIsThisJawn(new Set());
//=> 'Yo this jawn is an instance of Set'

When you're can javascript, but you're also a philly local.