Chendi Wu

Appearance

html
<!doctype html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>策略模式</title>
  </head>
  <body>
    <div class="eg2"></div>

    <script>
      const calcPrice = (() => {
        const sale = {
          '100_10': (price) => (price -= 10),
          '200_25': (price) => (price -= 25),
          '80%': (price) => (price *= 0.8),
        }

        function calcPrice(price, type) {
          if (!sale[type]) return '没有这个折扣'
          return sale[type](price)
        }

        calcPrice.add = (type, fn) => {
          if (sale[type]) return '该折扣已经存在'

          sale[type] = fn
          return '添加成功'
        }

        calcPrice.del = (type) => {
          delete sale[type]
        }

        return calcPrice
      })()

      calcPrice.add('70%', (price) => {
        return (price *= 0.7)
      })
      const res = calcPrice(320, '70%')
      console.dir(res)

      calcPrice.del('100_10')
      const res2 = calcPrice(320, '100_10')
      console.log(res2)
    </script>
  </body>
</html>