Why the order of LINQ to objects methods counts

Question

I read this question\'s answers that explain the order of the LINQ to objects methods makes a difference. My question is why?

If I write a LINQ to SQL query, it doesn\'t

Answer 1

It's perfectly legal to use side-effecting operations. Compare:

"crabapple"
    .OrderBy(c => { Console.Write(c); return c; })
    .Where(c => { Console.Write(c); return c > 'c'; })
    .Count();
"crabapple"
    .Where(c => { Console.Write(c); return c > 'c'; })
    .OrderBy(c => { Console.Write(c); return c; })
    .Count();