Constant string lenght

Question

CSharp question:
If I declare constant string anywhere and then use it's string.Lenght in code - will it be replaced with an integer value during compilation?

Code Example:

public const string InfoToDataSeparator = "#&#";  
  
private string dynamicData = "Some data before separator#&#Some data after separator";  
public void Main()  
{  
    int index = dynamicData.IndexOf(InfoToDataSeparator);  
    if (index < 0)  
        throw new(nameof(dynamicData) + " has no required data sepator");  
      
    Console.WriteLine(dynamicData[(index + InfoToDataSeparator.Length)..]); // Length usage  
}  

(P.S: I know about string.Split(args) method. In source code, there is a reason why I using such thing)

Answer 1

I'm interpreting your question to mean:

When the string is const, is code that references the
Length property of the string replaced with a
hard-coded absolute value (the string length)
at compile-time? Or does the compiler generate
code that accesses the Length property at run-time,
as it would for a non-const string?

Using your example:

public const string AnString = "An string value";  
  
Console.WriteLine(AnString.Length > 5);  
  

Does the compiler generate code that actually compares
the Length property to 5, or does it generate code that
literally uses the expression 15 > 5 because the length
of the string is fixed and can not be changed at run time?

Console.WriteLine(15 > 5);  
  

Or does it generate code that skips a comparison altogether
and just generates code that uses a true/false bool? e.g. -

Console.WriteLine(true);  
  

I haven't checked the Standard but I would expect that to
be an implementation-specific detail (or feature).

• Wayne