Check if all values are equal in a list
c#, lambda, linq
Solution
You can use `GroupBy`:
bool allEqual = orders.GroupBy(o => o.qty).Count() == 1;
or, little bit more efficient but less readable:
bool allEqual = !orders.GroupBy(o => o.qty).Skip(1).Any();
or, definitely more efficient using `Enumerable.All`:
int firstQty = orders.First().qty; // fyi: throws an exception on an empty sequence
bool allEqual = orders.All(o => o.qty == firstQty);
Problem
``` Class order { Guid Id; int qty; } ``` Using LINQ expression, how can I verify if the `qty` is the same for all orders in a list? Thanks in advance!