c # write one line of code from list to array

Question

Is it possible in C# to combine the Name properties of the List<Tag> object with a comma "," with a line command? "World,Tech,Science,Arts"

public class Tag
{
   public int Id { get; set; }
   public string Name { get; set; }
}

List<string> tagNames;
foreach (var tag in tags)
{
   tagNames.add(tag.Name);
}
string result = String.Join(",", tagNames);

I tried this but it doesn't work

string result = String.Join(",", tags.ForEach(t => t.Name));

You should use Select, not ForEach and make sure you have using System.Linq; — juharr
– juharr, Commented Dec 26, 2020 at 20:31
List's ForEach has done more damage for people's understanding of LINQ, than good for C# as a whole — Jonesopolis
– Jonesopolis, Commented Dec 26, 2020 at 20:40

Mureinik · Accepted Answer · 2020-12-26 20:37:30Z

3

ForEach runs a block of code. You're looking for Select that projects each element in a different form:

string result = String.Join(",", tags.Select(t => t.Name));

answered Dec 26, 2020 at 20:37

Mureinik

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Comments

Idle_Mind · Accepted Answer · 2020-12-26 22:10:21Z

2

Is it possible in C# to combine the Name properties of the List object with a comma "," with a line command?

Another one-liner using Aggregate instead of String.Join():

string result = tags.Select(t => t.Name).Aggregate((a, b) => (a + "," + b));

answered Dec 26, 2020 at 22:10

Idle_Mind

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