如何排序字符串列表？

Question

I have a list of persons List<person>

public class Person
{
    public string Age { get; set; }
}

their age sorrily is in string but is infact of type int and has values like "45", "70", "1" etc. . How can I sort the list from older to younger?

calling people.Sort(x => x.Age); doesn't give the desired result. thanks.

Answer 1

This should work (assuming that people is a List<Person> ) :

people = people.OrderByDescending(x => int.Parse(x.Age)).ToList();

If you don't want to create a new List , alternatively you can implement IComparable<T> for your class:

public class Person : IComparable<Person>
{
    public string Age { get; set; }

    public int CompareTo(Person other)
    {
        return int.Parse(other.Age).CompareTo(int.Parse(this.Age));
    }
}

Then you just need to use Sort method:

people.Sort();

Answer 2

You can cast each string to an int, then order them, largest to smallest:

var oldestToYoungest = persons.OrderByDescending(x => Int32.Parse(x.Age));

That should give you the desired result (assuming ages of "7", "22", and "105"):

105
22
7

If you sort them as strings, you won't get the desired result, as you found out. You'll end up with a list ordered alphabetically, like:

"7"
"22"
"105"