如何填充v8阵列?

时间:2022-07-02 06:56:10

I have a vector std::vector<std::string> path and I would like to copy it to a v8 array and return it from my function.

我有一个矢量std :: vector 路径,我想将它复制到v8数组并从我的函数返回它。

I have tried creating a new array

我试过创建一个新数组

v8::Handle<v8::Array> result;

and putting the values from path into result but with no luck. I've also tried several variations of

并将路径中的值放入结果但没有运气。我也尝试了几种变体

return scope.Close(v8::Array::New(/* I've tried many things in here */));

without success.

没有成功。

This is a similar question but I cant seem to duplicate the results.

这是一个类似的问题,但我似乎无法复制结果。

How do you populate v8 arrays?

你如何填充v8阵列?

2 个解决方案

#1


9  

This example directly from the Embedder's Guide seems very close to what you want - replace new Integer objects with new String objects.

直接来自Embedder指南的这个例子似乎非常接近你想要的 - 用新的String对象替换新的Integer对象。

// This function returns a new array with three elements, x, y, and z.
Handle<Array> NewPointArray(int x, int y, int z) {

  // We will be creating temporary handles so we use a handle scope.
  HandleScope handle_scope;

  // Create a new empty array.
  Handle<Array> array = Array::New(3);

  // Return an empty result if there was an error creating the array.
  if (array.IsEmpty())
    return Handle<Array>();

  // Fill out the values
  array->Set(0, Integer::New(x));
  array->Set(1, Integer::New(y));
  array->Set(2, Integer::New(z));

  // Return the value through Close.
  return handle_scope.Close(array);
}

I'd read up on the semantics of Local and Persistent handles because I think that is where you have got stuck.

我已经阅读了Local和Persistent句柄的语义,因为我认为这是你遇到的问题。

This line:

这一行:

v8::Handle<v8::Array> result;

Doesn't create a new array - It only creates a Handle that can later be filled in with an array.

不创建新数组 - 它只创建一个Handle,以后可以用数组填充。

#2


1  

To create a new array

创建新数组

    Handle<Array>postOrder = Array::New(isolate,5);
    //New takes two argument 1st one should be isolate and second one should 
    //be the number 

To Set the element in v8::array

在v8 :: array中设置元素

    int elem = 101; // this could be a premitive data type, array or vector or list 
    for(int i=0;i<10;i++) {
      postOrder->Set(i++,Number::New(isolate,elem));
    } 

To Get the element from v8::array

从v8 :: array获取元素

    for(int i=0; i<postOrder->Length();i++){
       double val = postOrder->Get(i)->NumberValue()
    }

    //Type conversion is important in v8 to c++ back and forth; there is good library for data structure conversion; **V8pp Header only Librabry**

Thanks!!

谢谢!!

#1


9  

This example directly from the Embedder's Guide seems very close to what you want - replace new Integer objects with new String objects.

直接来自Embedder指南的这个例子似乎非常接近你想要的 - 用新的String对象替换新的Integer对象。

// This function returns a new array with three elements, x, y, and z.
Handle<Array> NewPointArray(int x, int y, int z) {

  // We will be creating temporary handles so we use a handle scope.
  HandleScope handle_scope;

  // Create a new empty array.
  Handle<Array> array = Array::New(3);

  // Return an empty result if there was an error creating the array.
  if (array.IsEmpty())
    return Handle<Array>();

  // Fill out the values
  array->Set(0, Integer::New(x));
  array->Set(1, Integer::New(y));
  array->Set(2, Integer::New(z));

  // Return the value through Close.
  return handle_scope.Close(array);
}

I'd read up on the semantics of Local and Persistent handles because I think that is where you have got stuck.

我已经阅读了Local和Persistent句柄的语义,因为我认为这是你遇到的问题。

This line:

这一行:

v8::Handle<v8::Array> result;

Doesn't create a new array - It only creates a Handle that can later be filled in with an array.

不创建新数组 - 它只创建一个Handle,以后可以用数组填充。

#2


1  

To create a new array

创建新数组

    Handle<Array>postOrder = Array::New(isolate,5);
    //New takes two argument 1st one should be isolate and second one should 
    //be the number 

To Set the element in v8::array

在v8 :: array中设置元素

    int elem = 101; // this could be a premitive data type, array or vector or list 
    for(int i=0;i<10;i++) {
      postOrder->Set(i++,Number::New(isolate,elem));
    } 

To Get the element from v8::array

从v8 :: array获取元素

    for(int i=0; i<postOrder->Length();i++){
       double val = postOrder->Get(i)->NumberValue()
    }

    //Type conversion is important in v8 to c++ back and forth; there is good library for data structure conversion; **V8pp Header only Librabry**

Thanks!!

谢谢!!