<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=http://www.mamicode.com/{"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] );          }