Question

Was practicing Generics. Consider a stack method below. What is the best way of doing error checking other than throwing exceptions in a generic method. What if I want to return some result in this method.

public T pop()
{
    if (top >= 0)
        return arr[top--];
    return -1 or null;
}

Answer 1

The only thing you could do is return default(T), which is the default value for the type T (null for reference types, zero for integral types and zeroed-fields object for other value types). However, this is generally a bad idea as you’ll have no way to distinguish between a 0 that was popped or a 0 that indicates an error. Exceptions are generally the best way to go in such cases, but you could also change your method as follows:

public bool TryPop(out T value)
{
    if (top >= 0)
    {
        value = arr[top--];
        return true;
    }
    value = default(T);
    return false;
}