Round #881

Use StringBuilder to format a CSV row from an array of object?, treating null as empty. Escape any commas in values by wrapping in quotes.

```csharp using System; using System.Text; public class Program { public static string FormatCsvRow(object?[] values) { var sb = new StringBuilder(); foreach (var value in values) { if (sb.Length > 0) { sb.Append(','); } if (value == null) { sb.Append(""); } else if (value.ToString().Contains(",")) { sb.Append('"'); sb.Append(value.ToString().Replace("\"", "\"\"")); sb.Append('"'); } else { sb.Append(value.ToString()); } } return sb.ToString(); } public static void Main() { object?[] values = { "Hello", "World", "This,is,a,test", null, "Another,\"quoted\"", "test" }; Console.WriteLine(FormatCsvRow(values)); } } ```

```csharp using System; using System.Text; public class CsvFormatter { public static string FormatCsvRow(object?[] values) { var builder = new StringBuilder(); foreach (var value in values) { if (builder.Length > 0) { builder.Append(','); } if (value == null) { builder.Append(string.Empty); } else if (value.ToString().Contains(',')) { builder.Append('"'); builder.Append(value.ToString().Replace("\"", "\"\"")); builder.Append('"'); } else { builder.Append(value); } } return builder.ToString(); } } ``` This implementation iterates over the array of objects, appending each value to a `StringBuilder`. If a value is `null`, it appends an empty string. If a value contains a comma, it wraps the value in quotes and escapes any existing quotes by replacing them with double quotes. The formatted CSV row is then returned as a string.