在C#编程中字符串拼接是一种常见且基础的操作,广泛应用于各种场景,如动态生成SQL查询、构建日志信息、格式化用户显示内容等。然而,不同的字符串拼接方式在性能和内存使用上可能存在显著差异。今天咱们一起来看看在C#中字符串拼接的常见6种方式及其使用BenchmarkDotNet
进行性能分析对比。
BenchmarkDotNet是一个基于.NET开源、功能全面、易于使用的性能基准测试框架,它为.NET开发者提供了强大的性能评估和优化能力。通过自动化测试、多平台支持、高级统计分析和自定义配置等特性,BenchmarkDotNet帮助开发者更好地理解和优化软件系统的性能表现。
private const int IterationCount = 1000;
private const string StringPart1 = "追逐时光者";
private const string StringPart2 = "DotNetGuide";
private const string StringPart3 = "DotNetGuide技术社区";
private readonly string[] _stringPartsArray = { "追逐时光者", "DotNetGuide", "DotNetGuide技术社区" };
+
操作符 /// <summary>
/// 使用 + 操作符拼接字符串
/// </summary>
/// <returns></returns>
[Benchmark]
public string PlusOperator()
{
string result = StringPart1 + " " + StringPart2 + " " + StringPart3;
return result;
}
$
内插字符串 /// <summary>
/// 使用 $ 内插字符串拼接字符串
/// </summary>
/// <returns></returns>
[Benchmark]
public string InterpolatedString()
{
string result = $"{StringPart1} {StringPart2} {StringPart3}";
return result;
}
/// <summary>
/// 使用string.Format()拼接字符串
/// </summary>
/// <returns></returns>
[Benchmark]
public string StringFormat()
{
string result = string.Format("{0} {1} {2}", StringPart1, StringPart2, StringPart3);
return result;
}
/// <summary>
/// 使用string.Concat()拼接字符串
/// </summary>
/// <returns></returns>
[Benchmark]
public string StringConcat()
{
string result = string.Concat(StringPart1, " ", StringPart2, " ", StringPart3);
return result;
}
/// <summary>
/// 使用string.Join()拼接字符串
/// </summary>
/// <returns></returns>
[Benchmark]
public string StringJoin()
{
string result = string.Join(" ", _stringPartsArray);
return result;
}
/// <summary>
/// 使用StringBuilder.Append拼接字符串
/// </summary>
/// <returns></returns>
[Benchmark]
public string StringBuilderAppend()
{
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.Append(StringPart1);
stringBuilder.Append(" ");
stringBuilder.Append(StringPart2);
stringBuilder.Append(" ");
stringBuilder.Append(StringPart3);
return stringBuilder.ToString();
}
/// <summary>
/// 使用StringBuilder.AppendFormat拼接字符串
/// </summary>
/// <returns></returns>
[Benchmark]
public string StringBuilderAppendFormat()
{
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.AppendFormat("{0} {1} {2}", StringPart1, StringPart2, StringPart3);
return stringBuilder.ToString();
}
咱们分别以少量字符串拼接和大量字符串拼接为例,进行性能基准对比测试:
说明:
using BenchmarkDotNet.Attributes;
using System.Text;
namespace BenchmarkDotNetExercise
{
[MemoryDiagnoser]//记录内存分配情况
public class StringConcatenationBenchmark
{
private const int IterationCount = 1000;
private const string StringPart1 = "追逐时光者";
private const string StringPart2 = "DotNetGuide";
private const string StringPart3 = "DotNetGuide技术社区";
private readonly string[] _stringPartsArray = { "追逐时光者", "DotNetGuide", "DotNetGuide技术社区" };
#region 少量字符串拼接
/// <summary>
/// 使用 + 操作符拼接字符串
/// </summary>
/// <returns></returns>
[Benchmark]
public string PlusOperator()
{
string result = StringPart1 + " " + StringPart2 + " " + StringPart3;
return result;
}
/// <summary>
/// 使用 $ 内插字符串拼接字符串
/// </summary>
/// <returns></returns>
[Benchmark]
public string InterpolatedString()
{
string result = $"{StringPart1} {StringPart2} {StringPart3}";
return result;
}
/// <summary>
/// 使用string.Format()拼接字符串
/// </summary>
/// <returns></returns>
[Benchmark]
public string StringFormat()
{
string result = string.Format("{0} {1} {2}", StringPart1, StringPart2, StringPart3);
return result;
}
/// <summary>
/// 使用string.Concat()拼接字符串
/// </summary>
/// <returns></returns>
[Benchmark]
public string StringConcat()
{
string result = string.Concat(StringPart1, " ", StringPart2, " ", StringPart3);
return result;
}
/// <summary>
/// 使用string.Join()拼接字符串
/// </summary>
/// <returns></returns>
[Benchmark]
public string StringJoin()
{
string result = string.Join(" ", _stringPartsArray);
return result;
}
/// <summary>
/// 使用StringBuilder.Append拼接字符串
/// </summary>
/// <returns></returns>
[Benchmark]
public string StringBuilderAppend()
{
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.Append(StringPart1);
stringBuilder.Append(" ");
stringBuilder.Append(StringPart2);
stringBuilder.Append(" ");
stringBuilder.Append(StringPart3);
return stringBuilder.ToString();
}
/// <summary>
/// 使用StringBuilder.AppendFormat拼接字符串
/// </summary>
/// <returns></returns>
[Benchmark]
public string StringBuilderAppendFormat()
{
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.AppendFormat("{0} {1} {2}", StringPart1, StringPart2, StringPart3);
return stringBuilder.ToString();
}
#endregion
}
}
using BenchmarkDotNet.Attributes;
using System.Text;
namespace BenchmarkDotNetExercise
{
[MemoryDiagnoser]//记录内存分配情况
public class StringConcatenationBenchmark
{
private const int IterationCount = 1000;
private const string StringPart1 = "追逐时光者";
private const string StringPart2 = "DotNetGuide";
private const string StringPart3 = "DotNetGuide技术社区";
private readonly string[] _stringPartsArray = { "追逐时光者", "DotNetGuide", "DotNetGuide技术社区" };
#region 大量字符串拼接
/// <summary>
/// 使用 + 操作符拼接字符串
/// </summary>
/// <returns></returns>
[Benchmark]
public string BigDataPlusOperator()
{
string result = string.Empty;
for (int i = 0; i < IterationCount; i++)
{
result += StringPart1 + " " + StringPart2 + " " + StringPart3;
}
return result;
}
/// <summary>
/// 使用StringBuilder.Append拼接字符串
/// </summary>
/// <returns></returns>
[Benchmark]
public string BigDataStringBuilderAppend()
{
StringBuilder stringBuilder = new StringBuilder();
for (int i = 0; i < IterationCount; i++)
{
stringBuilder.Append(StringPart1);
stringBuilder.Append(" ");
stringBuilder.Append(StringPart2);
stringBuilder.Append(" ");
stringBuilder.Append(StringPart3);
}
return stringBuilder.ToString();
}
#endregion
}
}