This is my first question so hello to all users!
Is there a function in C# to quickly convert some collection to string and separate values with delimiter?
For example:
List<string> names --> string names = "John, Anna, Monica"
views:
126answers:
2
+15
A:
You can use String.Join. If you have a List<string> then you can call ToArray first:
List<string> names = new List<string>() { "John", "Anna", "Monica" };
var result = String.Join(", ", names.ToArray());
Edit: Actually, in .NET 4 you don't need the ToArray anymore, since there is an overload of String.Join that takes an IEnumerable<string>.
Quartermeister
2010-08-26 12:30:38
In C# 4 you no longer need to change List<string> to an array, IEnumerable<string> is accepted as well.
Simon Steele
2010-08-26 12:35:27
And if you're using .NET4 then you don't need the `ToArray` call.
LukeH
2010-08-26 12:35:34
+3
A:
You can also do this with linq if you'd like
var names = new List<string>() { "John", "Anna", "Monica" };
var joinedNames = names.Aggregate((a, b) => a + ", " + b);
Although I prefer the non-linq syntax in Quartermeister's answer and I think Aggregate might perform slower (probably more string concatenation operations).
Bob
2010-08-26 12:36:09
Thanks for the fast replies, both works fine. You're right I did a small performance measurement using Stopwatch class and the linq-way is much slower: String.Join(", ", names.ToArray()); --> took 18 ticksAggregate((a, b) => a + ", " + b) --> took 736 ticks
Andrzej Nosal
2010-08-26 13:09:28
Yeah I think `Aggregate` is better for Math type operations. With strings this operation it is similar to `for each` ing and just appending to a string which is very slow in inefficient because you are creating a new string for each item that exists in the list.
Bob
2010-08-26 13:26:11