A quick benchmark to test the 4 most common ways to concatenate strings (+, fmt.Sprintf, strings.Builder and strings.Join).
To test on your machine, run:
go test -bench=. -benchmem$ go test -bench=. -benchmem
goos: linux
goarch: amd64
pkg: scratchpad-go
cpu: AMD Ryzen 5 5600X 6-Core Processor
BenchmarkConcatStrings_Plus-12 51331621 21.97 ns/op 8 B/op 1 allocs/op
BenchmarkConcatStrings_Sprintf-12 11596424 102.9 ns/op 40 B/op 3 allocs/op
BenchmarkConcatStrings_StringsBuilder-12 64022565 18.46 ns/op 8 B/op 1 allocs/op
BenchmarkConcatStrings_Join-12 42522718 27.70 ns/op 8 B/op 1 allocs/op
BenchmarkConcatStringAndInt_Plus-12 51975021 22.21 ns/op 5 B/op 1 allocs/op
BenchmarkConcatStringAndInt_Sprintf-12 12212780 98.96 ns/op 21 B/op 2 allocs/op
BenchmarkConcatStringAndInt_StringsBuilder-12 56754538 20.43 ns/op 8 B/op 1 allocs/op
BenchmarkConcatStringAndInt_Join-12 38538142 28.96 ns/op 8 B/op 1 allocs/opThe + operator is the second fastest and tied for least memory while also being the most convenient, so it's probably the best option in the majority of cases.
Sprintf is the slowest and takes the most memory. Don't use it.
strings.Builder is the fastest yet probably the most cumbersome.
strings.Join is a great option for arrays of strings.