JavaScript使用对象注意

    var obj = {};    obj[1] = 1; // 进行了转化，将其变为字符串    obj['1'] = 2398;    writeObj(obj); // Object {1:2}    obj[{}] = true; // 将对象转化为字符串(调用toString)作为key    writeObj(obj);    obj[{x:1}] = true;// 将对象转化为字符串<span style="font-family: Arial, Helvetica, sans-serif;">(调用toString)</span><span style="font-family: Arial, Helvetica, sans-serif;">作为key</span>    writeObj(obj); // Object {1:2,[object Object]:true}    // 打印对象    function writeObj(obj){        var description = "";        for(var i in obj){            var property=obj[i];            description+=i+" = "+property+"\n";        }        alert(description);    }

注意：

    var date = new Date; // 当无须传递参数的时候，可以不用写上参数    document.writeln(date.getYear() + 1900);