Replace substrings with values from array

Question

I have a string like this:

string source = hello{1}from{2}my{3}world

And an array like this:

var valArray = new[] { "Val0", "Val1", "Val2", "Val3" };

I want to replace "{index}" substring with appropriate values from array.

I've already written the code, but it looks ugly

var valArray = new[] { "Val0", "Val1", "Val2", "Val3" };
var source = "hello{1}from{2}my{3}world";
var substr = source;
string pattern = $"{Regex.Escape(start)}{".+?"}{Regex.Escape(end)}";

foreach (Match m in Regex.Matches(source, pattern))
{
    var value = m.Groups[0].Value;
    var ind = Convert.ToInt32(m.Groups[0].Value.TrimStart(start.ToCharArray()).TrimEnd(end.ToCharArray()));
    substr = substr.Replace(value, valArray[ind]);
}
return substr;

Any tips how to get this solved?

Thanks!

Result string must be like this: "helloVal1fromVal2myVal3world" — Rasim Ismatulin
– Rasim Ismatulin, Commented Mar 19, 2016 at 14:44
if you source will be hello{2}from{1}my{3}world and var valArray = new[] { "Val0", "Val1", "Val2", "Val3" }; what should be the output? — Ivan Gritsenko
– Ivan Gritsenko, Commented Mar 19, 2016 at 14:52

Gediminas Masaitis · Accepted Answer · 2016-03-19 15:11:16Z

3

I think you're looking for String.Format:

string result = string.Format(source, valArray); // "helloVal1fromVal2myVal3world"

Just keep in mind that it's indexing from 0, not from 1.

edited Mar 19, 2016 at 15:11

answered Mar 19, 2016 at 14:43

Gediminas Masaitis

3,21218 silver badges38 bronze badges

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

6 Comments

Rasim Ismatulin Over a year ago

No code must automatic find and adjust all indexes {valArray} to valArray[index]

Ivan Gritsenko Over a year ago

Add valArray.Cast<object>().ToArray(), valArray will be treated as an obejct, not as array of objects to be passed as params.

weston Over a year ago

@IvanGritsenko that isn't true string.Format("hello{1}from{2}my{3}world", valArray); gives helloVal1fromVal2myVal3world just fine

Gediminas Masaitis Over a year ago

@weston Yep, you're right. I just looked at Ivan's comment and thought "yeah, that makes sense". Now I properly tested it - an array of strings works just fine.

Ivan Gritsenko Over a year ago

@weston, Surprisely it is not working on int[] or any other struct array.

|

Kalten · Accepted Answer · 2016-03-19 14:57:28Z

0

Use Regex.Replace(string input, string pattern, MatchEvaluator evaluator)

var valArray = new[] { "Val0", "Val1", "Val2", "Val3" };
var source = "hello{1}from{2}my{3}world";

string result = Regex.Replace(
    source,
    "{(?<index>\\d+)}",
    match => valArray[int.Parse(match.Groups["index"].Value)]);

answered Mar 19, 2016 at 14:57

Kalten

4,35226 silver badges34 bronze badges

Comments

weston · Accepted Answer · 2016-03-19 15:12:35Z

0

[Test]
public void SO_36103066()
{
    string[] valArray = new[] { "Val0", "Val1", "Val2", "Val3" };
    //prefix array with another value so works from index {1}
    string[] parameters = new string[1] { null }.Concat(valArray).ToArray(); 
    string result = string.Format("hello{1}from{2}my{3}world", parameters);
    Assert.AreEqual("helloVal0fromVal1myVal2world", result);
}

answered Mar 19, 2016 at 15:12

weston

55k23 gold badges151 silver badges209 bronze badges

Collectives™ on Stack Overflow

Replace substrings with values from array

3 Answers 3

6 Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

6 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related