Javascript 第二步，然后在promise中的第一步之前运行函数

这是我的代码：

var fs = require('fs');

var printMsg = function (msg) {
    console.log("printMsg: " + msg)
};

var myWrite = function (filename, content) {
    return new Promise(function (resolve, reject) {
        fs.writeFile(filename, content, function (err) {
            console.log("content: " + content);
            if (err || content.includes('Fail')) {
               console.log("promise rejected for content: '" + content + "'");
               reject("error writing");
            }
            else {
               console.log("promise resolved for content: '" + content + "'");
               resolve("ok");
            }
        });
    });
};

myWrite("test.txt", "Hello world")
    .then(myWrite("test.txt", "Failed"))
    .then(myWrite("test.txt", "How are you?"))
    .catch(printMsg);

在本例中，我预计事情将按以下顺序发生：

日志将打印内容“Hello world”

函数用“ok”解决它

日志将打印内容“失败”

函数以“写入错误”消息拒绝了它

下一个承诺将被跳过

catch将执行带有消息“error writing”的第二个承诺

实际结果非常混乱，所有承诺都是异步运行的，所有承诺都是在没有catch函数的情况下执行的

输出：

content: Hello world
promise resolved for content: 'Hello world'
content: How are you?
promise resolved for content: 'How are you?'
content: Failed
promise rejected for content: 'Failed'

输出会不时更改，也可以：

content: How are you?
promise resolved for content: 'How are you?'
content: Hello world
promise resolved for content: 'Hello world'
content: Failed
promise rejected for content: 'Failed'

如果我将内容日志移到“writeFile”函数之前，它将以异步顺序首先记录所有内容名称，这意味着所有承诺将一起执行。 有人能解释一下我做错了什么吗

---

谢谢你

。然后

接受函数作为参数，而不是调用函数的结果-即，在本例中，您将承诺传递给

。然后

-承诺不是函数在

中进行调用之前。然后

使用

（）=>

并退后观察Jaromanda X，非常感谢！）我真的不知道。。