Question

1. How do I smartly initialize an Array with two (or more) other arrays in C#?

   double[] d1 = new double[5];
   double[] d2 = new double[3];
   double[] dTotal = new double[8]; // I need this to be {d1 then d2}
   

2. Another question: How do I concatenate C# arrays efficiently?

Answer 1

You could use CopyTo:

double[] d1 = new double[5];
double[] d2 = new double[3];
double[] dTotal = new double[d1.Length + d2.Length];

d1.CopyTo(dTotal, 0);
d2.CopyTo(dTotal, d1.Length);