javascript – 如何将参数传递给promise函数

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.

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

和功能是类似的

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"));
  }
});

解决方法:

将你的Promise包装在一个函数中,否则它将立即开始工作.另外,您可以将参数传递给函数：

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"));
    }
  });
};

采用：

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