js-依次循环异步请求(普通/ES6)

╰+攻爆jí腚メ 2023-07-18 12:54 11阅读 0赞

要求：请求5次ajax,将结果依次显示在页面

老办法：用数组+定时器代替for循环

//递归 -------有顺序
             function getTime(j, length) {
                $start = new Date().getTime();
                Time(j, length);
            }
            function Time(j,length) {
                $.get(seturl, function (e) {
                    $end = new Date().getTime();
                    //js请求时间
                    //计算出相差天数
                    $date = $end - $start;
                    $seconds = Math.ceil($date / (1000));
                    $last = $seconds - e['time'];
                    console.log($seconds);
                    $html = $('<li>' + j + '  test1: ' + e["time"] + 's' + '   /   test2:  ' + $last + 's</li>');
                    $html.appendTo($('.list'));
                    //成功后，判断是否要接着执行
                    if (++j < length) {
                        getTime(j, length);
                    }
                    if (j == 6) {
                        //loading end
                        $('#loading').hide();
                    }
                }, 'json').error(function (XMLHttpRequest, textStatus, errorThrown) {
                    alert(XMLHttpRequest.status);
                    alert(XMLHttpRequest.readyState);
                    alert(textStatus);
                })
            }
            getTime(1, 6);

模拟请求：

新办法：ES6 async await

async function getTime() {
                for (var i = 1; i <6 ; i++) {
                    await Time(i);
                }
            }
    
          function Time(j) {
                $start = new Date().getTime();
                $.get(seturl, function (e) {
                    $end = new Date().getTime();
                    //js请求时间
                    //计算出相差天数
                    $date = $end - $start;
                    $seconds = Math.ceil($date / (1000));
                    $last = $seconds - e['time'];
                    //显示在页面上
                    $html = $('<li>' + j + '  test1: ' + e["time"] + 's' + '   /   test2:  ' + $last + 's</li>');
                    $html.appendTo($('.list'));
                    if (j == 5) {
                    // loading end
                    $('#loading').hide();
                    }
                }, 'json').error(function (XMLHttpRequest, textStatus, errorThrown) {
                    alert(XMLHttpRequest.status);
                    alert(XMLHttpRequest.readyState);
                    alert(textStatus);
                })
            }
    
        getTime();
    ```![](https://img2018.cnblogs.com/blog/1535391/201909/1535391-20190916123248980-504294697.png)