var person = {
 name: 'hello world',
 age: 22,
 sayHello:function(){
  alert('I\'m 'this.name ',and I\'m ' this.age 'years old');
 }
};
person.sayHello();//I'm hello world, and I'm 22 years old

window.color = "red";
var o = { color: "blue"};
function sayColor(){
  alert(this.color);
}
sayColor(); //"red"
o.sayColor = sayColor;
o.sayColor(); //"blue"
//也可以使用apply和call
sayColor.apply(o);//"blue"
sayColor.call(o);//"blue"