LINQ returning strange value using Select on a string

Question

This code return the int 49

IEnumerable<int> numbersList = numbers.Select(x => Convert.ToInt32(x));

int sum = numbersList.Sum();

the numbers variable is a string with the value 1.

if I use

numbers.Split(',').Select(x => Convert.ToInt32(x));

Then I get the correct answer. I know split passes back a string array so I used a string array with a single value of 1 instead of splitting and that worked too.

string[] sa = new string[] { "1" }

My question is does anyone know why using the select on a string return the wrong value?

Thanks.

Answer 1

When you use numbers.Select() you treat the string as a collection. It is a collection, but not a collection of substrings but a collection of characters.

You get the same result as if numbers was an array of characters, i.e { '1' }.

The result of Convert.ToInt32('1') is the character code for '1', which is 49.