<!DOCTYPE html><html><head><meta charset="utf-8"><title>W3Cschool教程(w3cschool.cn)</title></head><body><p>局部变量计数。</p><button type="button" onclick="myFunction()">计数!</button><p id="demo">0</p><script>var add = (function () { ???var counter = 0; ???return function () {return counter += 1;}})();function myFunction(){ ???document.getElementById("demo").innerHTML = add();}</script></body></html>js 闭包
原文地址：https://www.cnblogs.com/sea-stream/p/10259130.html