Populate a array

[Amil Patel]

How would you go about populate a array with random value then pass the array and its length to the function.
(example)
The array size is 6 it contains {-12,35,5,22.1,65,-9} it should return all positive value less than 40.

double addValue(const double array1[], int number)
{
  int sum = 0;
  for(int i=0;i<length;i++){
    if(array1[i] < 40 && array1[i] > 0){
    sum = sum + array[i];
    }
  }
  return sum;
}

[Script Coder]

use the rand() function. Google for more info

[Lowest0ne]

You should pass the length of the array as to the argument as "number", so your for loop looks like this:
for (int i = 0 ; i < number ; i++)

It would be tricky to return all of the values that meet the criteria, easier to do what you have done, return the sum.

sum should be a double.

[vlad from moscow]

You can not return "all positive numbers" because function can return only one object.
You could return a vector of all positive numbers. For example

std::vector<double> positiveNumbers( double a[], int size, double value )
{
   std::vector<double> v;

   for ( int i = 0; i < size; i++ )
   {
      if ( 0 < a[i] && a[i] < value ) v.push_back( a[i] );
   }

   return ( v );
}

If you have to do the same without the vector you should use a pointer to an allocated array

double * positiveNumbers( double a[], int size, double value )
{
   int count = 0;
   double *p = 0;


   for ( int i = 0; i < size; i++ )
   {
      if ( 0 < a[i] && a[i] < value ) ++count;
   }

   if ( count != 0 )
   {
      p = new double[count];

      for ( int i = 0, j = 0; i < size; i++ )
      {
         if ( 0 < a[i] && a[i] < value ) p[j++] = a[i];
      }
   }

   return ( p );
}

By the way you could use standard algorithm std::copy_if

[Lowest0ne]

The first value in an array created and returned like that should be the length of the array (such method would also protect against count ending up as zero).

[Amil Patel]

you know when you populate an array do you have to create a new array
example
double array2 [3] = { }; or no who can use one array and generate random number into the array?

[MrHutch]

You'd probably want to create a new one to be populated.

Though, Vlad's idea is the best; use a vector.

What happens if you create an array of three elements and you find four values that are less than 40? Because you're array is only three elements in size, you're going to lose that fourth value.

There are ways to dynamically size the array, sure, but the most obvious and simple solution is the vector class.