Checking for valid array size?

[Halo Fan]

Will this be enough to ensure a valid array?

if (max > 1)

I need to write a constructor for a class that creates an array of size max (or 100 if not specified). Obviously I cannot accept a value such as -1 but I am not sure if it can be broken in another way that the check for a positive value will not be enough. Here is the function:

QuickSort::QuickSort (int max = 100) 
{
	if (max > 1) //If the input is valid or not specified and deflats to 100...
	{
		theData = new long[max];
		maxSize = max;
	}
	else //If the input is invalid...
	{
		theData = new long[100];
		maxSize = 100;
	}

}

Thank you in advance for any thoughts.

EDIT: I forgot to mention that the variable "maxSize" is inherited from the protected section of a base class from which I am deriving the other classes (such as my QuickSort class). maxSize is of type int.

[SirSmilesaLot]

Asking the user to input array size is always dangerous!!!(what if he enters 20000 or some large no, which may not be available).
Have a fixed upper limit like 200 and check for it.

[Halo Fan]

I agree that there are a lot of silly things about this (why use a long when an int is the same size in my IDE???) but it is for an assignment for school so I must do what I can without changing how the class works.

For this assignment I will be comparing sorting algorithm efficiencies for n up to over 1,000,000 in some cases so I probably shouldn't fix an upper limit on it for this particular assignment, though I agree that it is a good suggestion for writing actual code someone might use.

Thank you for the post.

[SirSmilesaLot]

If u are using large inputs of upto 1,000,000 or more, pls make sure u have exception handling for memory failures else ur program mite crash during runtime, n ull be left wondering the reason!!