What function is more effective than combining several strings into one?
- Concatenation:
string1 + string2 - Format:
string.Format("{0}{1}", string1, string2) - Interpolation:
$"{string1}{string2}"
The winner: Interpolation (compared on the .NET SDK 8.0.101)
It will compare strings of lengths 10, 50, and 100 characters using 2, 3, and 4 parameters.
BenchmarkDotNet v0.13.12, Windows 11 (10.0.22631.3085/23H2/2023Update/SunValley3)
Intel Core i7-1065G7 CPU 1.30GHz, 1 CPU, 8 logical and 4 physical cores
.NET SDK 8.0.101
[Host] : .NET 8.0.1 (8.0.123.58001), X64 RyuJIT AVX-512F+CD+BW+DQ+VL+VBMI
DefaultJob : .NET 8.0.1 (8.0.123.58001), X64 RyuJIT AVX-512F+CD+BW+DQ+VL+VBMI
| Method | N | Mean | Error | StdDev | Median | Rank | Gen0 | Allocated |
|---|---|---|---|---|---|---|---|---|
| StringConcatenation2Variables | 10 | 23.01 ns | 0.866 ns | 2.470 ns | 22.80 ns | 2 | 0.0153 | 64 B |
| StringFormat2Variables | 10 | 114.30 ns | 5.254 ns | 15.409 ns | 112.16 ns | 11 | 0.0153 | 64 B |
| StringInterpolation2Variables | 10 | 20.91 ns | 1.227 ns | 3.617 ns | 20.61 ns | 1 | 0.0153 | 64 B |
| StringConcatenation3Variables | 10 | 28.77 ns | 1.692 ns | 4.990 ns | 28.90 ns | 3 | 0.0210 | 88 B |
| StringFormat3Variables | 10 | 130.09 ns | 4.847 ns | 14.291 ns | 128.23 ns | 12 | 0.0210 | 88 B |
| StringInterpolation3Variables | 10 | 23.37 ns | 0.932 ns | 2.733 ns | 22.63 ns | 2 | 0.0210 | 88 B |
| StringConcatenation4Variables | 10 | 31.36 ns | 1.254 ns | 3.676 ns | 30.57 ns | 4 | 0.0249 | 104 B |
| StringFormat4Variables | 10 | 186.45 ns | 3.926 ns | 11.074 ns | 186.99 ns | 14 | 0.0381 | 160 B |
| StringInterpolation4Variables | 10 | 29.86 ns | 1.323 ns | 3.837 ns | 28.86 ns | 3 | 0.0249 | 104 B |
| StringConcatenation2Variables | 50 | 31.11 ns | 1.032 ns | 3.011 ns | 30.39 ns | 4 | 0.0535 | 224 B |
| StringFormat2Variables | 50 | 110.26 ns | 3.905 ns | 11.392 ns | 108.49 ns | 11 | 0.0534 | 224 B |
| StringInterpolation2Variables | 50 | 31.87 ns | 1.661 ns | 4.897 ns | 30.43 ns | 4 | 0.0535 | 224 B |
| StringConcatenation3Variables | 50 | 44.81 ns | 2.027 ns | 5.815 ns | 44.08 ns | 6 | 0.0784 | 328 B |
| StringFormat3Variables | 50 | 161.62 ns | 6.306 ns | 18.194 ns | 158.91 ns | 13 | 0.0782 | 328 B |
| StringInterpolation3Variables | 50 | 41.05 ns | 1.124 ns | 2.999 ns | 40.32 ns | 5 | 0.0784 | 328 B |
| StringConcatenation4Variables | 50 | 78.14 ns | 4.136 ns | 12.194 ns | 79.20 ns | 8 | 0.1013 | 424 B |
| StringFormat4Variables | 50 | 244.85 ns | 16.759 ns | 49.152 ns | 227.13 ns | 15 | 0.1144 | 480 B |
| StringInterpolation4Variables | 50 | 58.92 ns | 4.143 ns | 12.149 ns | 54.30 ns | 7 | 0.1013 | 424 B |
| StringConcatenation2Variables | 100 | 41.32 ns | 0.885 ns | 1.942 ns | 40.60 ns | 5 | 0.1013 | 424 B |
| StringFormat2Variables | 100 | 162.61 ns | 8.944 ns | 26.089 ns | 161.42 ns | 13 | 0.1013 | 424 B |
| StringInterpolation2Variables | 100 | 55.00 ns | 3.344 ns | 9.861 ns | 58.34 ns | 7 | 0.1013 | 424 B |
| StringConcatenation3Variables | 100 | 84.22 ns | 5.356 ns | 15.794 ns | 87.77 ns | 9 | 0.1491 | 624 B |
| StringFormat3Variables | 100 | 317.76 ns | 15.301 ns | 44.876 ns | 321.16 ns | 16 | 0.1488 | 624 B |
| StringInterpolation3Variables | 100 | 78.48 ns | 5.385 ns | 15.877 ns | 78.29 ns | 8 | 0.1491 | 624 B |
| StringConcatenation4Variables | 100 | 101.91 ns | 5.415 ns | 15.967 ns | 102.54 ns | 10 | 0.1969 | 824 B |
| StringFormat4Variables | 100 | 387.59 ns | 24.477 ns | 72.170 ns | 375.04 ns | 17 | 0.2103 | 880 B |
| StringInterpolation4Variables | 100 | 102.01 ns | 7.233 ns | 19.556 ns | 96.01 ns | 10 | 0.1969 | 824 B |
String interpolation will work faster approximately in each test case. (small differences with concatenation can be ignored) And ease of use do it the winner of this small contest.