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    <script> /* 一个问题匹配多个解决方案，不一定用到哪个方案 可能随时新增方案 把多种方案以闭包的方式保存起来， 可以添加，可以删除 举例： 折扣方案 满800减700 满200减100 1折 */ const claPrice = (function(){
      const sale = {
      "800": (price) => price -= 700, "200": (price) => price -= 100, "10%": (price) => price *= 0.1, } function claPrice(price,type) {
      if(!sale[type]) return "没有这个折扣"; return sale[type](price); } claPrice.add = function(type,fn) {
      if(sale[type]) return "该折扣已经存在"; sale[type] = fn; return "添加成功"; } claPrice.remove = function(type) {
      delete sale[type]; } return claPrice; }()) claPrice.add("20%",(price) => price *= 0.2); claPrice.remove("20%"); console.log(claPrice(1000,"20%")); // const res = claPrice(900,"800"); // console.log(res);//200 </script>
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