解析:Promise.when 有很多承诺? [英] Parse: Promise.when with many promises?

问题描述

解析文档(https://www.parse.com/docs/js/symbols/Parse.Promise.html#.when ) 解释了在使用 Parse.Promise.when 时，指定一个承诺数组是 kosher 的:

Parse documentation ( https://www.parse.com/docs/js/symbols/Parse.Promise.html#.when ) explains that when using Parse.Promise.when, it is kosher to specify an array of promises:

var p1 = Parse.Promise.as(1);
var p2 = Parse.Promise.as(2);
var p3 = Parse.Promise.as(3);

var promises = [p1, p2, p3];
Parse.Promise.when(promises).then(function(r1, r2, r3) {
  console.log(r1);  // prints 1
  console.log(r2);  // prints 2
  console.log(r3);  // prints 3
});

……真甜！

但是，您真的必须在 then() 函数中列出每个承诺响应吗?如果您有一系列未知大小的承诺，并且不是很 DRY，则不太可行！

But, do you really have to list every single promise response in your then() function? Not really feasible if you have an array of promises of unknown size, and not very DRY!

我可以这样做吗?

Parse.Promise.when(promises).then(function(responses) {
  console.log(responses[0]);  // prints 1
  console.log(responses[1]);  // prints 2
  console.log(responses[2]);  // prints 3
});

?

推荐答案

您可以使用 JavaScript 的内置特殊变量，arguments 像这样

You can make use of JavaScript's builtin special variable, arguments like this

Parse.Promise.when(promises).then(function() {
  console.log(arguments[0]);  // prints 1
  console.log(arguments[1]);  // prints 2
  console.log(arguments[2]);  // prints 3
});

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