Code optimisation for foreach in C#

Question

Code:

string testquestions = "1,2,100,3,4,101,98,99";
string[] qidarray = testquestions.Split(',');

StringBuilder sb = new StringBuilder();

foreach (string s in qidarray)
{
    sb.Append(String.Format(@"({0}),",s));
}

string output= sb.ToString().Substring(0, sb.ToString().Length - 1);

Desired output =

(1),(2),(100),(3),(4),(101),(98),(99)

The code works. I want to know is this the best way for achieving the result. Is there a better way to achieve the desired result?

Is there a way not to use a foreach loop?

Use String.Join()

Adriano Repetti
– Adriano Repetti

2018-06-14 17:43:22 +00:00
Commented Jun 14, 2018 at 17:43 — Adriano Repetti
– Adriano Repetti, Commented Jun 14, 2018 at 17:43
This should be more appropriate for code review.

aloisdg
– aloisdg

2018-06-14 17:50:25 +00:00
Commented Jun 14, 2018 at 17:50 — aloisdg
– aloisdg, Commented Jun 14, 2018 at 17:50

user1672994 · Accepted Answer · 2018-11-05 05:22:36Z

8

This would do the trick. The code is first splitting the string and using linq, formatting to desired output.

var strToPrint = string.Join(",", testquestions.Split(',')
                       .Select(s => string.Format(@"({0})", s)));

Console Output

Console.WriteLine(string.Join(",", testquestions.Split(',')
                        .Select(s => string.Format(@"({0})", s))));

You can check the live fiddle here - https://dotnetfiddle.net/4zBqMf

Edit :

As suggested by @paparazzo, you can use string interpolation to write the syntax as

var strToPrint = string.Join(",", testquestions.Split(',').Select(s => $"({s})"));

Live fiddle - https://dotnetfiddle.net/xppLH2

edited Nov 5, 2018 at 5:22

answered Jun 14, 2018 at 17:45

user1672994

10.9k1 gold badge25 silver badges35 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

Venkat Over a year ago

fantastic. it worked. just one line of code. This is what I was looking for,

paparazzo Over a year ago

$"({s})" is maybe cleaner.

user1672994 Over a year ago

@paparazzo - Agreed. Added in my answer.

maccettura Over a year ago

@user1672994 you should use the real name: "string interpolation" rather than "string format short notation"

user1672994 Over a year ago

@maccettura - Done.

user3389475 · Accepted Answer · 2018-06-14 18:12:57Z

1

Here are some other ways using Replace.

string testquestions = "1,2,100,3,4,101,98,99";

string result = new StringBuilder("(" + testquestions + ")").Replace(",", "),(").ToString();

string result1 = "(" + testquestions.Replace(",", "),(") + ")";

string result2 = "(" + new Regex(",").Replace(testquestions, "),(") + ")";

answered Jun 14, 2018 at 18:12

user3389475

1742 silver badges8 bronze badges

1 Comment

Venkat Over a year ago

perfect and simple

Collectives™ on Stack Overflow

Code optimisation for foreach in C#

2 Answers 2

5 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

5 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related