Nested string interpolation

Question

I've faced an issue with nested string interpolation in C# 6.

For example, there is a string:

string test = "StartText MiddleText1 MiddleText2 EndText";

If I want to apply ToUpper() method for MiddleText1 only, I can do this way:

string test = $@"StartText {"MiddleText1".ToUpper()} MiddleText2 EndText";

But what if I want to apply a string method, for example Replace() for this part of string:

{"Middletext1".ToUpper()} MiddleText2

I expected that something like this will work:

string test = $@"StartText {"{"MiddleText1".ToUpper()} MiddleText2".Replace("x", "y")} EndText";

But this syntax is wrong - I've tried a lot variations, played with quotas but I couldn't get correct syntax for this purpose. I'd wish to not split the string in a different parts. Is there a way to solve it using interpolation feature only?

Answer 1

Stop trying to do everything in one line is my suggestion

The following is the answer

var middle = "MiddleText1";
middle = middle.ToUpper();

var middle2 = $"{middle} MiddleText2";
middle2 = middle2.Replace("x", "y");

string test = $"StartText {middle2} EndText";

Which, when you add it all together.

string test = $"StartText {$"{"MiddleText1".ToUpper()} MiddleText2".Replace("x", "y")} EndText";

In short, you were just missing a $

However, Even this is messy as i am not sure what all the replaces are for, where this text comes from, and what the issue is you are trying to solve