Question

What does this do exactly?

var counts = new Dictionary<string, int>();
for (int i = 0; i < 10; i++)
counts[string.Format("STA Thread Queue Worker Thread No. {0}", i + 1)] = 0;

Thanks

Answer 1

The first line will create a new Dictionary with strings as keys and int as values for these keys,
it is like a Hash Table.

The second line will execute the third line 10 times, with i from 0 to 9.

In the third line, we will store the string in the Dictionary together with its value in a way that it can be quicly looked up, with strings containing i + 1 which is 1 to 10 and set their corresponding value to 0.

STA Thread Queue Worker Thread No. 1 --> 0  
STA Thread Queue Worker Thread No. 2 --> 0  
...

Tip: It would be better to use an array for this, there is no need for hashing strings as they are static except for the integer. The string can thus be concatenated later when needed.

var counts = new int[10];
for (int i = 0; i < 10; i++)
    counts[i] = 0;

Or even shorter, as the elements are 0 by default:

var counts = new int[10];