blocks|key|73696|text|您可以在Promise.then块中调用下一轮的“循环”，如下所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|73697|function+do_thing(i)+{
++++//+Are+we+finished?+If+so,+return.
++++if+(i+==+list.length)+return;
++++Promise.do(action).then(function(result)+{
++++++++list[i]
++++++++//+Do+the+next+thing,+only+once+the+previous+thing+completed.
++++++++do_thing(i%2B1)
++++}
}
//+Start+at+the+first+thing.
do_thing(0)|code-block|syntax|javascript|73698|这方面的问题是，您失去了发生并行异步调用的好处--所有的东西都是序列化的--所以它会慢一些。使用jQuery承诺，您可以将索引附加到诺言对象.这个能在角度上工作吗？|73699|for+(var+i+=+0;i+<+list.length;+i%2B=1)+{
++++var+p+=+Promise.do(action)
++++p.index+=+i
++++p.then(function(result)+{
+++++++++//+this.index+is+the+value+of+i+so+do...
+++++++++list[this.index]+
++++}
}|73700|这里有一个小提琴，在jQuery风味中显示了这一点：http://jsfiddle.net/sifriday/0v6vr77y/|offset|length|73701|entityMap|0|LINK|mutability|MUTABLE|url|http://jsfiddle.net/sifriday/0v6vr77y/^0|0|0|0|0|Q|12|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Y|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|10|8|@]|9|@$M|11|N|12|1|13]]|A|$]]|$1|O|3|-4|5|6|7|14|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|V]]]]

You can call the next round of the 'loop' within the Promise.then block, like this:

<pre><code>function do_thing(i) {
 // Are we finished? If so, return.
 if (i == list.length) return;
 Promise.do(action).then(function(result) {
 list[i]
 // Do the next thing, only once the previous thing completed.
 do_thing(i+1)
 }
}
// Start at the first thing.
do_thing(0)
</code></pre>

The problem with this is that you lose the benefit of having parallel async calls happening - everything is serialised - so it will be slower. With a jQuery promise you could attach the index to the promise object... would this work in angular?

<pre><code>for (var i = 0;i &lt; list.length; i+=1) {
 var p = Promise.do(action)
 p.index = i
 p.then(function(result) {
 // this.index is the value of i so do...
 list[this.index] 
 }
}
</code></pre>

Here's a fiddle showing that in jQuery flavour: <a href="http://jsfiddle.net/sifriday/0v6vr77y/" rel="nofollow">http://jsfiddle.net/sifriday/0v6vr77y/</a>

blocks|key|73733|text|不要使用标准循环。使用Array.forEach代替。每次调用提供给forEach的函数时，您都会得到一个新的闭包，从而得到一个i的新副本|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|73734|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach^0|B|D|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

Don't use a standard loop. Use <a href="https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach" rel="nofollow">Array.forEach</a> instead. Every time the function supplied to forEach is called, you'll get a new closure and therefore a new copy of i

blocks|key|1312687|text|为此，我将尝试使用$q.all：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1312688|var+promises+=+[];

for+(var+i+=+0;+i+<+list.length;+i+%2B=+1)+{
++++promises.push(Promise.do(action));
}

$q.all(promises).then(function(results)+{
++++console.log(results);
});|code-block|syntax|javascript|1312689|从文件中：|1312690|返回将使用值的数组/散列解析的单个承诺，每个值对应于承诺数组/散列中相同索引/键下的承诺值。如果任何承诺都是通过拒绝来解决的，则此结果承诺将以相同的拒绝值被拒绝。|blockquote|1312691|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.angularjs.org/api/ng/service/$q^0|9|6|9|6|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|X|8|@$9|Y|A|Z|B|C]]|D|@$9|10|A|11|1|12]]|E|$]]|$1|F|3|G|5|H|7|13|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|14|8|@]|D|@]|E|$]]|$1|M|3|N|5|O|7|15|8|@]|D|@]|E|$]]|$1|P|3|-4|5|6|7|16|8|@]|D|@]|E|$]]]|Q|$R|$5|S|T|U|E|$V|W]]]]

I would try to use <a href="https://docs.angularjs.org/api/ng/service/$q" rel="nofollow"><code>$q.all</code></a> for this:

<pre><code>var promises = [];

for (var i = 0; i &lt; list.length; i += 1) {
 promises.push(Promise.do(action));
}

$q.all(promises).then(function(results) {
 console.log(results);
});
</code></pre>

From the documentation:

<blockquote>
 Returns a single promise that will be resolved with an array/hash of
 values, each value corresponding to the promise at the same index/key
 in the promises array/hash. If any of the promises is resolved with a
 rejection, this resulting promise will be rejected with the same
 rejection value.
</blockquote>

blocks|key|73764|text|绑定索引作为接收结果的函数的参数：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|73765|for+(var+i+=+0;i+<+list.length;+i%2B=1)+{
++++Promise.do(action).then((function(index,+result)+{
++++++++list[index]
++++}).bind(null,+i));
}|code-block|syntax|javascript|73766|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.mozilla.org/fr/docs/Web/JavaScript/Reference/Objets_globaux/Function/bind^0|0|2|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

<a href="https://developer.mozilla.org/fr/docs/Web/JavaScript/Reference/Objets_globaux/Function/bind" rel="nofollow">Bind</a> the index as an argument of the function receiving the result:

<pre><code>for (var i = 0;i &lt; list.length; i+=1) {
 Promise.do(action).then((function(index, result) {
 list[index]
 }).bind(null, i));
}
</code></pre>

blocks|key|73787|text|同意Bergi的评论，这看起来像臭名昭著的循环问题。然而，在注意到Bergi的评论之前，我输入了我的答案，下面是几个解决方案的建议：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|73788|for+(var+i+=+0;i+<+list.length;+i%2B=1)+{
++++var+callback+=+function(result)+{
++++++++list[arguments.callee.i]...
++++}
++++callback.i+=+i;
++++Promise.do(action).then(callback);
}|code-block|syntax|javascript|73789|或：|73790|for+(var+i+=+0;i+<+list.length;+i%2B=1)+{
++++var+callback+=+function(n)+{
++++++++return+function(result)+{
++++++++++++list[n]...
++++++++};
++++}(i);
++++Promise.do(action).then(callback);
}|73791|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Agree with Bergi's comment that this looks like the infamous loop issue. However, I typed my answer before noticing Bergi's comment, so here are a couple of proposals for solution:

<pre><code>for (var i = 0;i &lt; list.length; i+=1) {
 var callback = function(result) {
 list[arguments.callee.i]...
 }
 callback.i = i;
 Promise.do(action).then(callback);
}
</code></pre>

OR:

<pre><code>for (var i = 0;i &lt; list.length; i+=1) {
 var callback = function(n) {
 return function(result) {
 list[n]...
 };
 }(i);
 Promise.do(action).then(callback);
}
</code></pre>

I am making a series of http requests and I need to file the results into a list object when they return. I'm using angular promises.

Because the promises only resolve after the for loop is finished, they all get filed into the last index of list.

<pre><code>for (var i = 0;i &lt; list.length; i+=1) {
 Promise.do(action).then(function(result) {
 list[i] //i is always at last index because the for loop has already completed
 }
}
</code></pre>

How can I store the count of a for loop with promises that return in an arbitrary order?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我正在发出一系列http请求，当结果返回时，我需要将结果归档到list对象中。我用的是棱角分明的承诺。因为承诺只有在for循环完成后才会解析，所以它们都会被归档到列表的最后一个索引中。for (var i = 0;i < list.length; i+=1) { Promise.do(action).then(f...

问如何用以任意顺序返回的承诺存储for循环的计数？
EN

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问如何用以任意顺序返回的承诺存储for循环的计数？EN