/**
* the value will be all 2 , but if you change into *let*. that will not be happend
**/

let callbacks = [];
for(var i=0;i < 2; i++){
    callbacks.push(() => {
        console.log(i);
});
};

callbacks.forEach((callback) => callback());

const aFunction = () => {
    console.log('a function');
};

aFunction();