A.关联继承B.原型链继承C.构造函数继承D.组合继承
A.oStringObject instanceof StringB.typeof oStringObject ==’string’C.oStringObject is StringD.Object.toString.call(oStringObject)==’[String]’
A.if (x){function foo(){}}B.if (x){var foo =function(){}}C.if (x){foo =function(){}}D.ECMAScript明确的规范了块内函数,javascript实现了这个规范