How to convert a bool to a string in Go?

I am trying to convert a bool called isExist to a string (true or false) by using string(isExist) but it does not work. What is the idiomatic way to do this in Go?

Solution 1:

use the strconv package

docs

strconv.FormatBool(v)

func FormatBool(b bool) string FormatBool returns "true" or "false"
according to the value of b

Solution 2:

The two main options are:

1. strconv.FormatBool(bool) string
2. fmt.Sprintf(string, bool) string with the "%t" or "%v" formatters.

Note that strconv.FormatBool(...) is considerably faster than fmt.Sprintf(...) as demonstrated by the following benchmarks:

func Benchmark_StrconvFormatBool(b *testing.B) {
  for i := 0; i < b.N; i++ {
    strconv.FormatBool(true)  // => "true"
    strconv.FormatBool(false) // => "false"
  }
}

func Benchmark_FmtSprintfT(b *testing.B) {
  for i := 0; i < b.N; i++ {
    fmt.Sprintf("%t", true)  // => "true"
    fmt.Sprintf("%t", false) // => "false"
  }
}

func Benchmark_FmtSprintfV(b *testing.B) {
  for i := 0; i < b.N; i++ {
    fmt.Sprintf("%v", true)  // => "true"
    fmt.Sprintf("%v", false) // => "false"
  }
}

Run as:

$ go test -bench=. ./boolstr_test.go 
goos: darwin
goarch: amd64
Benchmark_StrconvFormatBool-8       2000000000           0.30 ns/op
Benchmark_FmtSprintfT-8             10000000           130 ns/op
Benchmark_FmtSprintfV-8             10000000           130 ns/op
PASS
ok      command-line-arguments  3.531s

Solution 3:

In efficiency is not too much of an issue, but genericity is, just use fmt.Sprintf("%v", isExist), as you would for almost all the types.