<script type="text/javascript">
  //创建一个Test对象
  function Test(){
  }
  var test = new Test();
  //创建一个对象
  var obj = new Object();
  //json 对象
  var json1 = {};
</script>

<script type="text/javascript">
  function Test(){
    this.name = "谭勇";
    this.age = 22;
    this.getName = function(){
      return this.name;
    }
    this.getAge = function(){
      return this.age;
    }
  }
  var test = new Test();
  console.log(test); //查看一下日志
  var obj = new Object();
  obj.name = "谭勇";
  obj.age = "22";
  obj.getName = function(){
    return this.name;
  };
  obj.getAge = function(){
    return this.age;
  };
  console.log(obj);  //查看下日志
  var json1 = {};
  json1["name"] = "谭勇";
  json1["age"] = 22;
  json1["getName"] = function(){
    return this.name;
  }
  json1["getAge"] = function(){
    return this.age;
  }
  console.log(json1); //查看下日志
</script>

<script type="text/javascript">
  function Test2(name,age){
    this.name = name;
    this.age = age;
    this.getName = function(){
      return this.name;
    }
    this.getAge = function(){
      return this.age;
    }
  }
  var test2 = new Test2("谭勇",22);
  console.log(test2);  //查看下日志
</script>

<script type="text/javascript">
  function Test3(){
    this.demo = function(param_str){
      return param_str;
    }
  }
  var test3 = new Test3();
  console.log(test3.demo("aaaaaaaaaaaaaaaaaaaa"));
</script>

<script type="text/javascript">
  function parent(){
    this.getStr = function(){
      return "test str";
    }
  }
  function son(){}
  son.prototype = new parent();
  var sona = new son();
  console.log(sona.getStr());
</script>

<script type="text/javascript">
  function extend(Child, Parent) {
  　　　　var p = Parent.prototype;
  　　　　var c = Child.prototype;
  　　　　for (var i in p) {
  　　　　　　c[i] = p[i];
  　　　　}
  }
  function parent(){
  }
  parent.prototype.getStr=function(){
    return "test str";
  }
  function son(){
  }
  extend(son,parent);
  var sona = new son();
  console.log(sona.getStr());
</script>

<script type="text/javacript">
  var str = "谭勇";
  String.prototype.getName = function(){
    var strs = "";
    for(var i=0;i<this.length;i++){
      strs += this[i];
    }
    return strs;
  }
  console.log(str.getName());
  console.log(str);
  console.log(str[0]);
</script>