JS global variable access

globals.js

myGlobal = 'I am accessible!'; // global var

(function(window) {
    console.log('Without clearing anything');
    
    console.log(window.myGlobal); // 'I am accessible!'
    console.log(myGlobal); // 'I am accessible!'
})(window);

(function(window) {
    console.log('Clearing window variable by passing in empty object');
    
    console.log(window.myGlobal); // undefined
    console.log(myGlobal); // 'I am accessible!'
})({});

(function(window) {
    console.log('"Clearing" myGlobal var by defining a private variable w/ same name');
    
    var myGlobal;
    console.log(window.myGlobal); // 'I am accessible!'
    console.log(myGlobal); // undefined
})(window);

(function(window) {
    console.log('Clearing both ways of accessing myGlobal');
    
    var myGlobal;
    console.log(window.myGlobal); // undefined
    console.log(myGlobal); // undefined
})({});

// All clearing was local only, outside of those functions it's untouched
console.log('Outside of function runs');

console.log(window.myGlobal); // 'I am accessible!'
console.log(myGlobal); // 'I am accessible!'