<script>
//使用in来检查某个对象中是否有该属性
var obj = new Object();
obj.name = "hh";
obj.age = "11";
console.log("name" in obj); // 输出值为true
console.log("address" in obj);
</script>
<script>
//使用in来检查某个对象中是否有该属性
var obj = new Object();
obj.name = "hh";
obj.age = "11";
console.log("name" in obj); // 输出值为true
console.log("address" in obj);
</script>