<!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>weakMap</title> </head> <body> <script> // WeakMap const oBtn1=document.querySelector("#btn1") const oBtn2=document.querySelector("#btn2") oBtn1.addEventListener("click",handleBtnClick,false) oBtn2.addEventListener("click",handleBtnClick,false) function handleBtn1Click(){ } function handleBtn2Click(){ } oBtn1.remove() oBtn2.remove() handleBtn1Click=null; handleBtn2Click=null; const oBtn3=new WeakMap() const oBtn4=new WeakMap() oBtn3.addEventListener("click",oBtnMap.get(oBtn3),false) oBtn4.addEventListener("click",oBtnMap.get(oBtn4),false) oBtn3.remove() oBtn4.remove() </script> </body> </html>