FactoryFunction/closure/returning function
function createGreeting(language){
return function(firstname, surname){
if (language === 'en'){
console.log('hello ' + firstname + ' ' + surname);
}
if (language === 'es'){
console.log('hola ' + firstname + ' ' + surname);
}
}
}
var greetEnglish = createGreeting('en');
var greetSpanish = createGreeting('es');
greetSpanish('hosei', 'Cierro');
greetEnglish('joseph', 'friend');