andrelandgraf

// timeouts are handy to fake async calls
// setTimeout(callback function, 1500 /*milliseconds*/, 'parameters');
function doSomething(name, callback){
    // 2.) task 1: we execute console.log('1');
    console.log('1');
    // 3.) task 1: we execute setTimeout. Set timeout creates a new task (task 2) that will be executed in 1500 milliseconds from now on
    setTimeout(callback, 1500, name);
    // 4.) task 1: we execute console.log('2');
    console.log('2');
}

andrelandgraf

// the scope of a let variable is the current block scope
// the scope of a var variable is the current function scope (if there is no function, than the scope is global)

// using var in this example will execute the loop and compute var i to the value 10 
// than the timeout callbacks will callback one after the other and access i which is globally set to 10
for(var i = 0; i < 10; i++){
    setTimeout(function () {
        console.log(i);
    }, 1500, i);
}

andrelandgraf

const myString = "Foo Bar";
const needle = "fOO";
let isCaseInsensitive = myString.includes(needle)); // => isCaseInsensitive is false
isCaseInsensitive = myString.toUpperCase().includes(needle.toUpperCase()); // => isCaseInsensitive is true