I have the following code:
var days = new string[] { "1", "2", "3", "4" });
I need to convert days to a string as following:
string daysConverted = "'1','2','3','4'";
I tried using string.Join:
var daysConverted = string.Join("','", days);
but I am getting:
"1','2','3','4" // missing quotes at the beginning and at the end.
I can concatenate a quote at both sides but I was wondering if there is any syntax to do it in one shot.
You should wrap the strings into ' before joining them:
var result = String.Join(",", days.Select(s => "'" + s + "'"));
System.Linq?
dont want. It may be the best but not the right answer for your question.You have to add it at the end and beginning also because Join will only combine two strings. Having said this when combining "1" and "2" with a speaterator of ',' you get "1','2" where the seperator is just added between the two elements.
As of MSDN:
Concatenates all the elements of a string array, using the specified separator between each element.
In the end the following solution seems to be best in terms of memory and speed because you have least number of string-concatenations (two for start and end and one for every element --> 2 + n).
var daysConverted = "'" + string.Join("','", days) + "'";
Well, speaking about minimal string concatenations, here is a solution utilizing LINQ Aggregate and StringBuilder. It's not so concise, but performs...zero concatenations.
var daysConverted = days.Aggregate(new StringBuilder(), (sb, s) =>
(sb.Length > 0 ? sb.Append(",") : sb).Append("'").Append(s).Append("'"))
.ToString();
I can concatenate a quote at both sides but I was wondering if there is any syntax to do it in one shot.
Not in an optimized way. string.Join internally uses a StringBuilder to compose the string. Cheating around string.Join would make your code less clear (for example by using tricky LINQ statements) AND slower.
In the end, the classical way that @HimBromBeere suggests is the best one.
+ operator is converted to a string.Concat. See right pane of sharplab.io . The problem is that the string.Concat returns a string, so it has to allocate it. using a string.Concat inside of a string.Join means you are allocating temporary strings just to use them for string.Join.