Javascript如何在運行多個IF語句後獲得價值

我有一個Object，我想循環並針對一系列IF語句運行。每個IF語句使得HTTP Request。 HTTP Request的結果被推送到Array。我需要在循環對象之後執行一個函數。Javascript如何在運行多個IF語句後獲得價值

如何在循環和IF語句完成後才執行函數？

代碼：

function myFunction(Object, res) { 
    var resultArray; 
    for (var obj in Object) { 
     if (something is true) { 
      //do something 
      resultArray.push(result) 
     } 
    } 
    //After the for loop is confirmed finished, do callback 
    res(resultArray) 
}

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2013-06-03 Rob

這會工作，這取決於你的'做something'是幹什麼的，如果它做動畫或'get's什麼它不可能奏效。另外，不要使用'Object'作爲變量，它是一個保留字，很多 – Blowsie

如果你正在'做些什麼'通過ajax發出這些HTTP請求，確保你要同步執行它們。換句話說，確保在執行'res（resultArray）'之前獲得響應。另外請記住，HTTP請求是昂貴的，在1個HTTP請求中將對象發送到服務器，然後將結果數組發送回服務器會更有效嗎？ –

@Blowsie是的，我的示例中使用了變量名稱。這不工作，因爲我正在發出一個HTTP請求，並在我得到響應之前繼續前進。 – Rob

我覺得你還是可以做到這一點異步。首先，你需要獲得所有屬性你的對象：

//Gather up all the properties; 
var properties = []; 
for(var property in object) if(object.hasOwnProperty(property) { 
    properties.push(property); 
} 

//Array of results 
var resultsArray = []; 


//This is a named, self-invoked function that basically behaves like a loop. The 
//loop counter is the argument "i", which is initially set to 0. The first if 
//is basically the loop-termination condition. If i is greater than the 
//total number of properties, we know that we're done. 
// 
//The success handler of the ajax call is where the loop is advanced. This is also 
//where you can put your if condition to check if something is true, so that you 
//can insert the data into the results array. At the end of the success handler, 
//you basically call the named self-invoked function, but this time with the 
//loop counter incremented. 
(function iterateOverProperties(i) { 
    if(i < properties.length) { 
     var property = properties[i]; 
     var value = object[property]; 

     //assuming jQuery just for demonstration 
     jQuery.ajax({ 
      url: "someurl", 
      data: value; 
      success: function(data) { 
       if(something is true) { 
        resultArray.push(data); 
       } 

       iterateOverProperties(++i); 
      } 
     }); 
    } else { 
     res(resultArray); 
    } 
})(0);

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2013-06-03 16:37:50

Javascript如何在運行多個IF語句後獲得價值

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