// Example 1
function identify() {
  return this.name.toUpperCase();
}
function speak() {
  var greet = "Hi, " + identify.call(this);
  console.log(greet);
}
var me = {name : "Kyle"};
var you = {name : "Jen"};

identify.call(me); // KYLE
identify.call(you); // JEN
speak.call(me); // Hi, KYLE
speak.call(you); // Hi, JEN


// Example 2
var add = function(x, y) {
  this.val = x + y;
};
var obj = {
  val: 0
};
add.apply(obj,[2,8]);
// 1st, 2nd arguments
console.log(obj, val); // 10
add.call(obj,2,8);
// 1st, 2nd, 3rd arguments
console.log(obj, val); // 10