Szathmáry László honlapja @ DEIK

string.Join

csharp> var li = new List<string> {"aa", "bb", "cc", "dd"}

csharp> string.Join("", li)
"aabbccdd"

csharp> string.Join(",", li)
"aa,bb,cc,dd"

csharp> string.Join("--", li)
"aa--bb--cc--dd"

csharp> var li = new List<int> {1, 2, 3, 4}
csharp> string.Join("", li) // works with numbers too
"1234"

It also works with numbers, for instance. No need to convert the numbers to strings first.

string.Concat

If you simply want to concatenate the elements, then you can also use string.Concat(), which is equivalent to joining where the delimiter is the empty string.

csharp> var li = new List<string> {"aa", "bb", "cc", "dd"}

csharp> string.Concat(li)
"aabbccdd"

csharp> var li = new List<int> {1, 2, 3, 4}
csharp> string.Concat(li) // works with numbers too
"1234"

It also works with numbers.

20180403d

string.Join

string.Concat