js的split方法和join方法

splitAndJoin() {
      const date = "2021-03-08";
      const s = date.split("-");
      console.log("=========", s);
    }

split会把字符串转成一个数组，按分割符，分隔开。

    splitAndJoin() {
      const date = "2021-03-08";
      let s = date.split("-");
      console.log("jjjjjj", s);
      console.log("jjjjjjjjjjjjjjj", s.join("-"));
    }

join把数组每个项用指定的字符连接起来成字符串。