SOURCE

"use strict";

window.q = 123;
function f2() {
    let test = {
            q: 567,
            f2: ()=>{
                 console.log(this.q);
            },
            f3: function(){
                 console.log(this.q);
            }
    };
    
   
    test.f3();
    test.f2();
}

f2();