Understanding Aggregate.. well ish anyway

Combine values from list items
var x is of type collection/list/array


var out = x.Aggregate(<seed,>(acc,item) => acc + item);

acc is the accumulator which is returned
item is each item

At position acc + item, a function can exist to provide extra functionallity.

item is never the first item of the array unless you seed from a blank string.

For example:

var out = x.Aggregate("",(acc,item) => acc + item);