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c++referencedynamic-arrays

How to modify array inside function which doesn't take this array as parameter

What I need is to modify pTab array inside modifyAA(int a) function. How can I achieve this?

Example Code:

int modifyAA(int a); 

int main()
{
  *pTab=new int[10]; int a=13;

  for(int i=0;i<=9;i++)
      pTab[i]=88;                      

  modifyAA(a);      
  //I'd like to have pTab to be modified after function invoke
return 0;
}

modifyAA(int a){

  for(int i=0;i<=9;i++)
     pTab[i]=pTab[i]+1; 

a=a+pTab[0];  
return a;                  
};

Is it possible to modify array when function doesn't take it as parameter ?

Solution

  • You can use a global variable for the pointer to the first element of the dynamic array:

    int * pTab;

int printAA(int a)
{
    for (unsigned int i = 0 i != 10; ++i)
    {
        ++pTab[i];
    }
    return a + pTab[0];
}

int main()
{
    pTab = new int[10];

    // populate

    printAA(13);
}