str := fmt.Sprintf("Hello, %s! You are %d years old.", name, age)

fmt.Fprintf(&buf, "Hello, %s!", name)

var builder strings.Builder
fmt.Fprintf(&builder, "Hello, %s!", name)
str := builder.String()

str := strconv.Itoa(123) // 整数转字符串

str := "Hello, " + name + "!"

tmpl, _ := template.New("test").Parse("Hello, {{.Name}}!")
tmpl.Execute(&buf, data)

func BenchmarkSprintf(b *testing.B) {
    name := "John"
    age := 30
    for i := 0; i < b.N; i++ {
        _ = fmt.Sprintf("Hello, %s! You are %d years old.", name, age)
    }
}

func BenchmarkBuilderFprintf(b *testing.B) {
    name := "John"
    age := 30
    for i := 0; i < b.N; i++ {
        var builder strings.Builder
        fmt.Fprintf(&builder, "Hello, %s! You are %d years old.", name, age)
        _ = builder.String()
    }
}

func BenchmarkConcat(b *testing.B) {
    name := "John"
    age := 30
    ageStr := strconv.Itoa(age)
    for i := 0; i < b.N; i++ {
        _ = "Hello, " + name + "! You are " + ageStr + " years old."
    }
}