js замыкания

//пример 1
function buildCoveTickerMaker( transport ){
  return function ( name ){
    document.write("Here is your transportation ticket via the "+transport+".<br/>"+
    "Welcome to the Closures Cove, "+name+"!");
  }
}
var getSubmarineTicket = buildCoveTickerMaker("submarine"); //запоминаем транспорт
getSubmarineTicket("Vlad"); //выводим
//Here is your transportation ticket via the submarine
//Welcome to the Closures Cove, Vlad!

//пример 2
function get2X( x ){ //10
  return function ( y ){ //2
    return x*x*y;
  }
}
var get2XPlus = get2X( 10 ); //запоминаем что x = 10
document.write( get2XPlus( 2 ) ); //выводим 200