Question

我在JavaScript中有以下代码：

for (var i = 0; i< uuids.length; i++){
     var attr = uuids[i]
     var uuid = attr["uuid"];
     console.log("uuid is: " + uuid)
     multiClient.hget(var1, var2, function(err, res1){
          console.log("uuid INSIDE hget is: " + uuid)
      }
}

hget是一种异步方法。以下是此功能的打印件：

"uuid is: 1"
"uuid is: 2"
"uuid INSIDE hget is: 2"
"uuid INSIDE hget is: 2"

我希望在hget函数中保存uuid的上下文，所以我会得到：

"uuid is: 1"
"uuid is: 2"
"uuid INSIDE hget is: 1" (where all the context before the loop has saved for this uuid)
"uuid INSIDE hget is: 2" (where all the context before the loop has saved for this uuid)

我该怎么做？

Answer 1

以下代码

multiClient.hget(var1, var2, function(err, res1){
   console.log("uuid INSIDE hget is: " + uuid)
}

uuid值将是异步操作完成时的值。

您可以使用匿名函数执行此操作并将uuid的值复制到其他变量uuid_temp并使用该值，如下所示。

(function() {
   var uuid_temp = uuid;
   multiClient.hget(var1, var2, function(err, res1){
      console.log("uuid INSIDE hget is: " + uuid_temp); //note uuid_temp here
   }
}());

JavaScript /保存可变内部异步函数的上下文

1 个答案: