雖然循環和回調返回不同的結果

我有一個while循環匹配一個條件來過濾來自mongodb的數據。但是，當我使用回調時，我只收到console.log的一個結果。如果我在while循環中使用console.log，我應該會收到三個條目。爲什麼只有一條數據使其回調？雖然循環和回調返回不同的結果

while(i--) { 
    if (0 >= [friday, saturday, sunday].indexOf(results[i].selectedDate)) { 
     theWeekend = results[i]; 
     console.log(theWeekend); //returns three results (correct) 
    } 
} 
callback(err, theWeekend) 
console.log(theWeekend); //returns one results (incorrect)

正確性

{ _id: 56fffb5ceb76276c8f39e3f3, 
    url: 'http://londonist.com/2015/11/where-to-eat-and-drink-in-balham', 
    title: 'Where To Eat And Drink In... Balham | Londonist', 
    selectedDate: Fri Apr 01 2016 01:00:00 GMT+0100 (BST), 
    __v: 0 } 
{ _id: 56fffb8eeb76276c8f39e3f5, 
    url: 'https://news.ycombinator.com/item?id=11404770', 
    title: 'The Trouble with CloudFlare | Hacker News', 
    selectedDate: Sun Apr 03 2016 01:00:00 GMT+0100 (BST), 
    __v: 0 } 
{ _id: 56fffb6ceb76276c8f39e3f4, 
    url: 'http://wellnessmama.com/13700/benefits-coconut-oil-pets/', 
    title: 'Benefits of Coconut Oil for Pets - Wellness Mama', 
    selectedDate: Sat Apr 02 2016 01:00:00 GMT+0100 (BST), 
    __v: 0 }

不正確的數據

{ _id: 56fffb6ceb76276c8f39e3f4, 
    url: 'http://wellnessmama.com/13700/benefits-coconut-oil-pets/', 
    title: 'Benefits of Coconut Oil for Pets - Wellness Mama', 
    selectedDate: Sat Apr 02 2016 01:00:00 GMT+0100 (BST), 
    __v: 0 }

來源

2016-04-03 Rhys Edwards

['Array.prototype .filter（）']（https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter） – Andreas

您需要使用一個數組來存儲所有的結果如下：

var theWeekends = [] 
while(i--) { 
    if (0 >= [friday, saturday, sunday].indexOf(results[i].selectedDate)) { 
     theWeekends.push(results[i]); 

    } 
} 
callback(err, theWeekends) 
console.log(theWeekends); //returns 3 results (correct)

來源

2016-04-03 07:45:11 chriskelly

當然啊。謝謝 –

雖然循環和回調返回不同的結果

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