<!doctype html><html lang="en"><head><meta charset="UTF-8"><title>Document</title></head><script>var stu ={m: function(){var self = this;console.log(this === stu); // ==> true;function f(){//When a nested function is called, this does not point to the context in which the outer function is calledconsole.log(this === stu); // ==> false; If you want to access an external function this I need to take the external function this Save it in a variable.console.log(self === stu); // ==> true;}f();}}</script><body></body></html>