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CSharp · Console

/Program.cs

using System;
					
public class Program
{
	public static void Main()
	{
		string original = "foo bar foo $ bar $ foo bar $ ";  
		string result = original;
		int index = original.IndexOf("$")+1;	
		if (index > 0) result = (original.Substring(0, index)  + original.Substring(index).Replace("$", "")).Replace("  ", " ").Trim();
			
		Console.WriteLine(result);
		string desired_output = "foo bar foo $ bar foo bar"; 
		Console.WriteLine(desired_output == result);
	}
}