function checkThis() {
    return this;
}
console.log(checkThis()); // ?

// --------------------------------------- 

var obj = {
    prop: "hello",
    getProp: function() {
        return this.prop;
    }
};
console.log(obj.getProp()); // ?

// --------------------------------------- 

function myFunc() {
    return this.a;
}
var obj = {
    a: 'obj-a',
    myFunc: myFunc
};
const a = 'global-a';          // ES6 <<<< GOOGLE IT 
console.log(myFunc()); // ? 


// --------------------------------------- 

var obj1 = {
    name: "obj1",
    print: function() {
        console.log(this.name);
    }
};
var obj2 = { name: "obj2" };
obj2.print = obj1.print;
obj2.print();  // ? 


// --------------------------------------- 

function outer() {
    var inner = () => {
        console.log(this);    // ES6 <<<< GOOGLE IT 
    }
    inner();
}
outer.call("Hello"); // ? 


// --------------------------------------- 

var obj = {
    a: 1,
    getA: function() {
        return function() {
            return this.a;
        }
    }
};
var retrieveA = obj.getA();
console.log(retrieveA()); // ? 


// --------------------------------------- 

var cat = {
    sound: "meow",
    speak: function() {
        return this.sound;
    }
};
var dog = {
    sound: "woof"
};
console.log(cat.speak.call(dog)); // ? 


// --------------------------------------- 

var car = {
    brand: "Toyota",
    getBrand: function() {
        return this.brand;
    }
};
var getCarBrand = car.getBrand;
console.log(getCarBrand()); // ?