JSON格式的属性访问 - 点号或者中括号

	
<script>
  //JSON格式的attr访问 - 点号或者中括号 -注意：中括号里面可以放变量
  
 var imgData={ "name":"图片描述和图片相对路径", "title":"logo图片","url":"logo.png" };
 alert( imgData.name ); 
 alert( imgData["name"] );  
 var str="name" ;  alert( imgData[str] );  
  

 var json1={"name":"这里是一组图片的文字描述和图片相对路径",
  			"title":["logo图片","图片1","图片2","图片3"],
             "url":["logo.png","1.png","2.png","3.png"]
              };
alert( json1.name);
alert( json1.url  );
alert( json1.url[1] );

alert( json1["name"]);
alert( json1["url"]  );
alert( json1["url"][1] );


var json2 ={ "name":"图片描述和图片相对路径",
  			 "imgData":[
  			   { "name":"图片1", "title":"logo图片1","url":"logo1.png" } , 
  			   { "name":"图片2", "title":"logo图片2","url":"logo2.png" }  ,
  			   { "name":"图片3", "title":"logo图片3","url":"logo3.png" }   
  			   ]
              };
 alert( json2.name );
 alert( json2.imgData ); 
 alert( json2.imgData[0].name );     

 alert( json2["name"] );
 alert( json2["imgData"] ); 
 alert( json2["imgData"][0].name );      

</script>

	<script>
         var json1= {
         	"name":"july", 
         	"age":18, 
         	"imgSrc":["1.png","2.png","3.png" ]
         };

 	 /* for-in 访问属性名称：  
	            name
			    age
                imgSrc*/
         for( var attr in json1){
         	console.log( attr);
            }
      /* for-in 访问属性值：
           july
           18
           ["1.png", "2.png", "3.png"]
            */
       
         for( var attr in json1){
         	console.log( json1[attr]);  
     
         }
	</script>

  // for-in 访问对象的属性名、属性值
         for( var attr in window){
            	 console.log(   attr ); 
          }

         for( var attr in window){
         	    console.log(  window[attr] ); 
         }

  // for-in 访问对象的属性名、属性值
         for( var attr in document){
            	 console.log(   attr ); 
         }

         for( var attr in document){
         	    console.log(  document[attr] ); 
         }