Function Factories using Closures

With Closures, this kind of function factories are possible.

These are good in order that it lets people to avoid writing code with DRY principle.

function makeGreeting(lan) {
    return function(first, last) {
        if (lan === 'en') {
            console.log('Hello ' + first + ' ' + last);
        }

        if (lan === 'es') {
            console.log('Hola ' + fisrt + ' ' + last);
        }

    }
}

var greetEn = makeGreeting('en');
var greetSp = makeGreeting('es');

greetEn('jim', 'ragon'); // outputs 'Hello jim ragon'
greetSp('jim', 'Carry'); // outputs 'Hola jim Carry'

So even though the makeGreeting execution context has ended when we called makeGreeting twice, it was executed individually and make seperate execution contexts, so even though the execution contexts were removed from the call stack, the closure memory of lan variable would still be there to hold the information.