Question

I have a struct TableRow and an array table of such structs:

table = new TableRow[10];

Now I want to find and manipulate the content of one of the structs in the array.
I use Array.Find to search the right array element:

var tr = Array.Find( table, tRow => tRow.color == 'red' );
tr.count++;

Problem is that structs are value types and so the Find method returns a copy of the struct that I want to manipulate. Changing this copy does not change the struct in the array.

I can’t seem to find any way to instruct the Find method to return the struct by reference.

Answer 1

You can’t change the way Find() works for value types. You can either convert your struct to a class — typically we only use struct for very small (<= 16 byte) value types that represent a “single” value anyway. MSDN has good guidance on struct vs class here: Chossing Between Classes and Structs

Or you can use FindIndex() to get the position in the array, and then use that to modify the field.

var pos = Array.FindIndex(table, tRow => tRow.color == 'red');

if (pos >= 0)
{
    table[pos].count++
}