思路

动态生成正则表达式

由于下面的转义之后前面会带\所以这里要连\一起捕获

const re = new RegExp(
    value
      .replace(/(\\.)/g, "$1.*?")
  )

用正则表达式去过滤结果

这里题目故意挖了个坑，正则表达式的符号要转义

replace(/([\\\/\(\)\+\*\?\:\\[\]\^\$])/g, "\\$1")

完整代码如下

        function listSuggests(value) {
        if (!value) return [];
        const re = new RegExp(
          value
            .replace(/([\\\/\(\)\+\*\?\:\\[\]\^\$])/g, "\\$1")
            .replace(/(\\.)/g, "$1.*?")
        );
        const items = window.items;
        const result = items.filter((i) => re.test(i));
        return result;
      }
      function onInput(evt) {
        const suggests = listSuggests(evt.currentTarget.value.trim());
        const s = document.getElementsByClassName("js-suggest")[0];
        const ul = s.children[0];
        ul.innerHTML = "";
        if (!suggests.length) return s.classList.add("hide");
        s.classList.remove("hide");
        ul.innerHTML = suggests.map((i) => `<li>${i}</li>`).join("");
      }
      function suggest(items) {
        window.items = items;
        const el = document.getElementsByClassName("js-input")[0];
        // el.addEventListener("change", onInput);
        el.addEventListener("input", onInput);
        onInput({ currentTarget: el });
      }