| 1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677 | <!DOCTYPE html><html lang="en"><head>  <meta charset="UTF-8">  <meta http-equiv="X-UA-Compatible" content="IE=edge">  <meta name="viewport" content="width=device-width, initial-scale=1.0">  <title>Document</title>  <style>    #div1 {      width: 200px;      height: 200px;      background: pink;    }  </style></head><body>  <div id="div1"></div>  <script>    var div1 = document.getElementById('div1')    //1.当前对象引用中,  谁的事件 this指向就是谁    // div1.onclick = function(){    //   console.log(this)    // }    //2.在定时器当中, this指向window    // var timer = setInterval(function () {    //   console.log(this)    // }, 2000)    // div1.onclick = function () {    //   var timer = setInterval(function () {    //     console.log(this)    //   }, 2000)    // }    //3.在对象下面 this指向对象本身    // var person = {    //   name: 'zs',    //   age: 20,    //   eat: function(){    //     console.log(this)    //   }    // }    // person.eat()    //4.在函数内 this指向window    // function xx(){    //   console.log(this)    // }    // xx()    div1.onclick = function(){      console.log(this,'a')      var timer = setInterval(function(){        console.log(this,'b')      },2000)      abc()          }    var abc = function(){      console.log(this,'c')    }    console.log(this,'d')    /*       div   a        d  window      window b       a  div      window c       c  window       window d       b  window        */  </script></body></html>
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