C# – Sort List Descending

clambdasorting

In c# (3.0 or 3.5, so we can use lambdas), is there an elegant way of sorting a list of dates in descending order? I know I can do a straight sort and then reverse the whole thing,

docs.Sort((x, y) => x.StoredDate.CompareTo(y.StoredDate));
docs.Reverse();

but is there a lambda expression to do it one step?

In the above example, StoredDate is a property typed as a DateTime.

Best Answer

Though it's untested...

docs.Sort((x, y) => y.StoredDate.CompareTo(x.StoredDate));

should be the opposite of what you originally had.

Related Solutions

C# – How to calculate someone’s age based on a DateTime type birthday

An easy to understand and simple solution.

// Save today's date.
var today = DateTime.Today;

// Calculate the age.
var age = today.Year - birthdate.Year;

// Go back to the year in which the person was born in case of a leap year
if (birthdate.Date > today.AddYears(-age)) age--;

However, this assumes you are looking for the western idea of the age and not using East Asian reckoning.

Python – How to sort a list of dictionaries by a value of the dictionary

The sorted() function takes a key= parameter

newlist = sorted(list_to_be_sorted, key=lambda d: d['name'])

Alternatively, you can use operator.itemgetter instead of defining the function yourself

from operator import itemgetter
newlist = sorted(list_to_be_sorted, key=itemgetter('name'))

For completeness, add reverse=True to sort in descending order

newlist = sorted(list_to_be_sorted, key=itemgetter('name'), reverse=True)

Best Answer

Related Solutions

C# – How to calculate someone’s age based on a DateTime type birthday

Python – How to sort a list of dictionaries by a value of the dictionary

Related Topic