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StringBuilder Text Accumulation

StringBuilder accumulates mutable text efficiently across a loop. Convert the finished buffer to a string when passing it to code that expects immutable text. Use a .NET 8+ console project; replace Program.cs with this C# example.

Read the syntax

StringBuilder accumulates mutable text efficiently across a loop. Convert the finished buffer to a string when passing it to code that expects immutable text. Use a .NET 8+ console project; replace Program.cs with this C# example.

One mutable buffer receives each fragment. The condition adds separators between items without a trailing comma.

Syntax

builder.Append(value); builder.ToString()

Examples

StringBuilder Text Accumulation

Use a .NET 8+ console project; replace Program.cs with this C# example.

using System;
using System.Text;
var builder = new StringBuilder();
for (int i = 1; i <= 3; i++)
{
    if (i > 1) builder.Append(", ");
    builder.Append("item-").Append(i);
}
Console.WriteLine(builder.ToString());
  1. Expected output: item-1, item-2, item-3
  2. One mutable buffer receives each fragment. The condition adds separators between items without a trailing comma.
  3. Use interpolation for short fixed messages.

Best practices

  • Use interpolation for short fixed messages.
  • Keep mutable builders local rather than sharing them between concurrent callers.

Runtime & versions

.NET runtime. Feature availability depends on the language and runtime version used by your project; consult the official reference below.

C# language reference

Specifications & further reading