//index.jsconst fs = require('fs')function isFileExisted() {    return new Promise(function(resolve, reject) {        fs.access('input.txt', (err) => {            if (err) {                reject(err.message);            } else {                resolve('existed');            }        })    })}(async() => {    try {        var res = await isFileExisted();        console.log(res);    } catch(error){        console.log(error);    }})();

准备一个input.txt文件

运行 ：node index.js

打印：existed

修改“index.js“里面的“input.txt“为“input1.txt“

打印：ENOENT: no such file or directory,......