如何将参数传递给promise函数 [英] How to pass parameter to a promise function

问题描述

这似乎是一个愚蠢的问题，但我是这个主题的新手。我正在研究节点js上的promises。我想将参数传递给promise函数。但是我无法理解。

this might seem a silly question but I am a newbie in this topic. I am working on promises on node js. And I want to pass parameter to a promise function. However I could not figure it out.

someModule.someFunction.then(username, password,function(uid) {
  /*stuff */
}

和函数类似

var someFunction = new Promise(username, password, function(resolve, reject) {
  /*stuff using username, password*/
  if ( /* everything turned out fine */ ) {
    resolve("Stuff worked!");
  } else {
    reject(Error("It broke"));
  }
});

推荐答案

将你的Promise包裹在一个函数中，或者它将立即开始工作。另外，你可以将参数传递给函数：

Wrap your Promise inside a function or it will start to do its job right away. Plus, you can pass parameters to the function:

var someFunction = function(username, password) {
  return new Promise(function(resolve, reject) {
    /*stuff using username, password*/
    if ( /* everything turned out fine */ ) {
      resolve("Stuff worked!");
    } else {
      reject(Error("It broke"));
    }
  });
}

然后，使用它：

someModule.someFunction(username, password).then(function(uid) {
  /* stuff */
})

 

ES6：

const someFunction = (username, password) => {
  return new Promise((resolve, reject) => {
    /*stuff using username, password*/

    if ( /* everything turned out fine */ ) {
      resolve("Stuff worked!");
    } else {
      reject(Error("It broke"));
    }
  });
};

使用：

someModule.someFunction(username, password).then(uid => {
  /* stuff */
});

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