JSFiddle - React, Tailwind, and code Playground

JavaScript

var myClass = {
    globalVar : {
        total : 100
    },
    myFunction : {
        getTotal : function() {
            console.log(this);
            return this.globalVar.total;
        }
    },
};

// Uncaught TypeError: Cannot read property 'total' of undefined 
alert(myClass.myFunction.getTotal() );