老师 第二段代码是GET请求的使用方法 第三四段代码是POST请求传不同参数的使用方法 第一段代码是什么意思

//
<script src="https://unpkg.com/axios@0.19.2/dist/axios.min.js"></script>

    <script>
      const URL = "https://www.imooc.com/api/http/search/suggest?words=js";

      axios(URL, {
        method: "post",
        // 请求时的头部信息
        headers: {
          "Content-Type": "application/x-www-form-urlencoded",
          // 'Content-Type': 'application/json'
        },
        // 通过请求头携带
        params: {
          username: "YangLiJun",
        },
        // 通过请求体携带
        // "Content-Type": "application/x-www-form-urlencoded",
        data: "sex=male&age=18",

        // 'Content-Type': 'application/json'
        // data: {
        //   sex: "male",
        //   age: 18,
        // },

        // timeout: 10,

        // withCredentials: true
      })
        .then((response) => {
          console.log(response.data.data);
        })
        .catch((err) => {
          console.log(err);
        });
</script>

//GET请求
<script src="https://unpkg.com/axios@0.19.2/dist/axios.min.js"></script>

    <script>
      const URL = "https://www.imooc.com/api/http/search/suggest?words=js";
      axios
        .get(URL, {
          params: {
            username: "YangLiJun",
          },
        })
        .then((response) => {
          console.log(response);
        })
        .catch((err) => {
          console.log(err);
        });
    </script>

//POST请求-传名值对形式
<script src="https://unpkg.com/axios@0.19.2/dist/axios.min.js"></script>

    <script>
      const URL = "https://www.imooc.com/api/http/search/suggest?words=js";
      axios
        .post(URL, "username=YangLiJun&age=18")  //传名值对形式，请求体自动解析Content-                                                         Type: application/x-www-form-urlencoded
        .then((response) => {
          console.log(response);
        })
        .catch((err) => {
          console.log(err);
        });
    </script>

//POST请求-传对象形式
<script src="https://unpkg.com/axios@0.19.2/dist/axios.min.js"></script>

    <script>
      const URL = "https://www.imooc.com/api/http/search/suggest?words=js";

      axios
        .post("https://www.imooc.com/api/http/json/search/suggest?words=js", {
          username: "YangLiJun",  //传对象形式，请求体自动解析Content-Type:                                                       application/json;charset=UTF-8，不需要设置Content-Type
          age: 18,
        })
        .then((response) => {
          console.log(response);
        })
        .catch((err) => {
          console.log(err);
        });
    </script>