javascript/ jQuery Best Practise

• 理解 JS 的 new 和 prototype 

var person = new Object();
person.firstName = "John";
person.lastName = "Deo";

person.sayHi = function(){
  return "Hi there";
};         

var createPerson = function(fristName, lastName) {
  return {
    firstName: firstName,
    lastName: lastName,
    sayHi : function() {
         return "Hi there";
    }
  };
};

var johnDeo = createPerson("John", "Deo");
var janeDeo = createPerson("Jane", "Deo");

function F(){};  
F.prototype = oldObject;  
var newObject = new F();

• 避免多次使用查询相同dom元素 

function theFunction(name, profession) {
    alert("My name is " + name + " and I am a " + profession + ".");
}
theFunction("John", "fireman");
theFunction.apply(undefined, ["Susan", "school teacher"]);
theFunction.call(undefined, "Claude", "mathematician");