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returning an array

biplav17 (159)
I am trying to return array by refrence. Seems like i did a mistake somewhere. could you please correct me?
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float *pointer;
  pointer = returnarray;
  return pointer;


The problem is when I am getting it
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float arrayc[2];
    (arrayc[0], arrayc[1]) = *computepoints(n);


thank you in advance
Last edited on
histrungalot (272)
Many things going on. More code please.
Last edited on
closed account (zb0S216C)
You cannot return an array, only a pointer to a dynamically allocated region of memory. Some compilers may allow it, but a standard-compliant one won't.

Simple as.

Wazzak
biplav17 (159)
but cant you return it was a refrence? I have done that pretty sure thats allowed
closed account (zb0S216C)
Yes you can (depends which compiler you use. Microsoft's compiler wouldn't allow it, the last time I checked), but why would you? Returning a private array? That'll break encapsulation (unless you declare the method constant). Returning a global or local array? Just access it directly.

The implementation looks like this: <TYPE>(&<FUNC_ID>(<PARAMETERS>))[<ARR_SIZE>];

Wazzak
Last edited on
biplav17 (159)
well i need to return two values from A function. So I am putting them in a array and returning by refrence. I use mingw
closed account (zb0S216C)
No! Don't do that! Returning local variables isn't a good idea. In fact, it's heavily discouraged. Returning an array (not a reference to one, but a local one) is illegal. You'll have to dynamically allocate the array and return a pointer to it, like so:

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int *ReturnArray(const unsigned int);

int main()
{
    int *MyArray(ReturnArray(3));
    
    delete [] MyArray;
    return(0);
}

int *ReturnArray(const unsigned int Len)
{
    return(new int[Len]);
}


Wazzak
closed account (DSLq5Di1)
^ That is an ugly solution. If the values are related, why not use a structure?
closed account (zb0S216C)
@Sloppy9: It's an ugly world. The things is, we don't know what types of value he/she is returning. If the structure is large, DMA is inevitable.

Wazzak
biplav17 (159)
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float *computepoints(int nameofcircle)
{
    float returnarray[2];
   if (nameofcircle ==1)
   {
       returnarray[0] = -4.5;
       returnarray[1] = 3.5;
    }
   else if (nameofcircle ==2)
   {
       returnarray[0] = -3.5;
       returnarray[1] = 3.5;

   }
   else if (nameofcircle ==3)
   {
       returnarray[0] = -2.5;
       returnarray[1] = 3.5;

   }
   else if (nameofcircle ==4)
   {
       returnarray[0] = -1.5;
       returnarray[1] = 3.5;

   }
   else if (nameofcircle ==5)
   {
       returnarray[0] = -4.5;
       returnarray[1] = 2.8;

   }
   else if (nameofcircle ==6)
   {
       returnarray[0] = -3.5;
       returnarray[1] = 2.8;
   }
   else if (nameofcircle ==7)
   {
       returnarray[0] = -2.5;
       returnarray[1] = 2.8;

   }
   else if (nameofcircle ==8)
   {
       returnarray[0] = -1.5;
       returnarray[1] = 2.8;

   }
   else if (nameofcircle ==9)
   {
       returnarray[0] = -4.5;
       returnarray[1] = 2.1;

   }
   else if (nameofcircle ==10)
   {
       returnarray[0] = -3.5;
       returnarray[1] = 2.1;

   }
   else if (nameofcircle ==11)
   {
       returnarray[0] = -2.5;
       returnarray[1] = 2.1;

   }
   else if (nameofcircle ==12)
   {
       returnarray[0] = -1.5;
       returnarray[1] = 2.1;

   }
   else if (nameofcircle ==13)
   {
       returnarray[0] = -4.5;
       returnarray[1] = 1.4;

   }
   else if (nameofcircle ==14)
   {
       returnarray[0] = -3.5;
       returnarray[1] = 1.4;

   }
   else if (nameofcircle ==15)
   {
       returnarray[0] = -2.5;
       returnarray[1] = 1.4;
   }
   else if (nameofcircle ==16)
   {
       returnarray[0] = -1.5;
      returnarray[1] = 1.4;

   }
   else if (nameofcircle ==17)
   {
       returnarray[0] = -4.5;
       returnarray[1] = 0.7;

   }
   else if (nameofcircle ==18)
   {
       returnarray[0] = -3.5;
       returnarray[1] = 0.7;

   }
   else if (nameofcircle ==19)
   {
       returnarray[0] = -2.5;
       returnarray[1] = 0.7;

   }
   else if (nameofcircle ==20)
   {
       returnarray[0] = -1.5;
       returnarray[1] = 0.7;

   }
   else if (nameofcircle ==21)
   {
       returnarray[0] = -4.5;
       returnarray[1] = 0;

   }
   else if (nameofcircle ==22)
   {
       returnarray[0] = -3.5;
       returnarray[1] = 0;

   }
   else if (nameofcircle ==23)
   {
       returnarray[0] = -2.5;
       returnarray[1] = 0;

   }
   else if (nameofcircle ==24)
   {
       returnarray[0] = -1.5;
       returnarray[1] = 0;

   }
   else if (nameofcircle ==25)
   {
       returnarray[0] = -4.5;
       returnarray[1] = -0.7;

   }
   else if (nameofcircle ==26)
   {
       returnarray[0] = -3.5;
        returnarray[1] = -0.7;

   }
   else if (nameofcircle ==27)
   {
       returnarray[0] = -2.5;
        returnarray[1] = -0.7;

   }
   else if (nameofcircle ==28)
   {
       returnarray[0] = -1.5;
        returnarray[1] = -0.7;

   }
   else if (nameofcircle ==29)
   {
       returnarray[0] = -4.5;
       returnarray[1] = -1.4;

   }
   else if (nameofcircle ==30)
   {
       returnarray[0] = -3.5;
       returnarray[1] = -1.4;

   }
   else if (nameofcircle ==31)
   {
       returnarray[0] = -2.5;
       returnarray[1] = -1.4;

   }
   else if (nameofcircle ==32)
   {
       returnarray[0] = -1.5;
       returnarray[1] = -1.4;

   }
   else if (nameofcircle ==33)
   {
       returnarray[0] = -4.5;
       returnarray[1] = -2.1;

   }
   else if (nameofcircle ==34)
   {
       returnarray[0] = -3.5;
       returnarray[1] = -2.1;

   }
   else if (nameofcircle ==35)
   {
       returnarray[0] = -2.5;
       returnarray[1] = -2.1;

   }
   else if (nameofcircle ==36)
   {
       returnarray[0] = -1.5;
       returnarray[1] = -2.1;

   }
   else if (nameofcircle ==37)
   {
       returnarray[0] = -4.5;
       returnarray[1] = -2.8;

   }
   else if (nameofcircle ==38)
   {
       returnarray[0] = -3.5;
       returnarray[1] = -2.8;

   }
   else if (nameofcircle ==39)
   {
       returnarray[0] = -2.5;
       returnarray[1] = -2.8;

   }
   else if (nameofcircle ==40)
   {
       returnarray[0] = -1.5;
       returnarray[1] = -2.8;

   }
   float *pointer;
   pointer = returnarray;
   return pointer;
}


there. I am returning that type of variables. Dont say why those if statements. It is complicated.
biplav17 (159)
I am trying to get the x and y co-ordinates of where the drawing should be made when I get the input from the user.
closed account (DSLq5Di1)
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struct point_t
{
    float x, y;
};

point_t computepoints(int nameofcircle)
{
    point_t pt;

   if (nameofcircle ==1)
   {
       pt.x = -4.5;
       pt.y = 3.5;
    }
    ...

    return pt;
}

point_t a = computepoints(n);
biplav17 (159)
I returned it. However, there is problem on this line
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point_t cor;
 cor = computepoints( nameofcircle);

biplav17 (159)
well thanks I figured out my problem.
thank you very much all of you
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