## **this關鍵字指向問題** ### 1.在事件中，指向當前對象 ``` <div id="div">div</div> <script> var div = document.getElementById("div"); div.onclick=function(){ console.log(this) } </script> ``` ### 2.在方法中，誰調用方法指向誰 ``` <script> setTimeout(()=>{ console.log(this) }) </script> ``` ### 3.在構造函數中，指向實例化的對象 ``` <script> function Person(name,age){ this.name = name; this.age = age; this.sayThis = function(){ console.log(this); } } var a = new Person("a",12); a.sayThis(); </script> ```