Promise_04中async与await结合读取文件&发送AJAX--shangguigu听课笔记

以你之姓@ 2023-10-06 17:27 20阅读 0赞

### async与await结合读取文件 ###

/**
     * resource  1.txt  2.txt  3.txt文件内容
     */
    
    const fs = require('fs');
    const util = require('util');
    const mineReadFile = util.promisify(fs.readFile);
    //async 与 await
    async function main(){
        
        try{
        
            //读取第一个文件的内容
            let data1 = await mineReadFile('./resource/1a.txt');
            let data2 = await mineReadFile('./resource/2.txt');
            let data3 = await mineReadFile('./resource/3.txt');
            console.log(data1 + data2 + data3);
        }catch(e){
        
            console.log(e.code);
        }
    }
    main();

### async与await结合发送AJAX ###

<!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <title>async与await结合发送AJAX</title>
    </head>
    <body>
        <button id="btn">点击获取段子</button>
        <script>
            //axios
            function sendAJAX(url){
         
                return new Promise((resolve, reject) => {
         
                    const xhr = new XMLHttpRequest();
                    xhr.responseType = 'json';
                    xhr.open("GET", url);
                    xhr.send();
                    //处理结果
                    xhr.onreadystatechange = function(){
         
                        if(xhr.readyState === 4){
         
                            //判断成功
                            if(xhr.status >= 200 && xhr.status < 300){
         
                                //成功的结果
                                resolve(xhr.response);
                            }else{
         
                                reject(xhr.status);
                            }
                        }
                    }
                });
            }
    
            //段子接口地址 https://api.apiopen.top/getJoke
            let btn = document.querySelector('#btn');
    
            btn.addEventListener('click',async function(){
         
                //获取段子信息
                let duanzi = await sendAJAX('https://api.apiopen.top/getJoke');
                console.log(duanzi);
            });
        </script>
    </body>
    </html>