obj.html

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Object</title>

    <script>
      var snail = {
        name : 'wu',
        birth : 1992,
        school : 'lu',
        score : null,
        'middle-school' : 'LL NO.1'
      };
      snail.name;   //'Xavier'
      snail.birth;  //1994
      snail['middle-school']; //'SS NO.2'
      snail['name'];  //'Xavier'
      snail['girlfriend'];  //undefined:girlfriend不存在
      //JS的对象是动态类型，你可以自由的给一个对象添加或删除属性
      snail.route = 'xiaomi';
      snail.weight = 182;
      /*
      var snail = {
        name : 'Xavier',
        birth : 1994,
        school : 'SS',
        score : null,
        'middle-school' : 'SS NO.2',
        route : 'YB',
        weight : 170
      };
      */
      //检测对象是否有这个属性的方法
      if (!('name1' in snail)) {
        alert(snail.toString())
      }
      //有些属性不一定是snail的，有可能是snail继承的 判断是否是自己的属性 用下面方法来判断
      var s = {
        name : 'Snail'
      };
      s.hasOwnProperty('name'); //true
      s.hasOwnProperty('toString'); //fasle
    </script>

  </head>
  <body>

  </body>
</html>