如何在节点js的readFile函数中添加承诺

fs.readFile(answer, 'utf8', function (err, data) {
                    var dataArray = data.split(/\r?\n/).filter(entry => entry.trim() != '');
                 console.log(dataArray);  // **Line 1**
                 });
                 console.log(dataArray);  // **Line2**
        }

首先执行第2行代码，然后执行第1行代码

var data = fs.readFileSync(answer, 'utf8');
var dataArray = data.split(/\r?\n/).filter(entry => entry.trim() != '');
console.log(dataArray);

如何在节点js的readFile函数中添加承诺

fs.readFile(answer, 'utf8', function (err, data) {
                    var dataArray = data.split(/\r?\n/).filter(entry => entry.trim() != '');
                 console.log(dataArray);  // **Line 1**
                 });
                 console.log(dataArray);  // **Line2**
        }

首先执行第2行代码，然后执行第1行代码

var data = fs.readFileSync(answer, 'utf8');
var dataArray = data.split(/\r?\n/).filter(entry => entry.trim() != '');
console.log(dataArray);