英文:
What is the most efficent way to print arrays in golang
问题
我是你的中文翻译助手，以下是翻译好的内容：
我刚开始学习编程，想了解更多关于内置函数的知识：
这是一个程序示例：
func main() {start := time.Now()fmt.Println(os.Args)fmt.Println(time.Since(start))}
它的输出结果是：
[A B C D E F G H I J K L M N O P] 124.009µs
这是我的 for 循环示例：
package mainimport ("fmt""os""time")func main() {start := time.Now()var s stringfor i := 0; i < len(os.Args); i++ {s += os.Args[i] + " "}fmt.Println(s)fmt.Println(time.Since(start))}
它的输出结果是：
/tmp/go-build994847456/b001/exe/main A B C D E F G H I J K L M N O P 25.71µs
我原本期望标准库中的内置函数会更快。
切片会让我的代码效率降低吗？
我应该使用 for 循环还是标准库的 fmt.Println？
我也对 strings.Join(os.Args[1:], " ") 的执行时间为 74.293µs 感到困惑。
英文:
I'm new to programming and wanted know more about the built-in functions:
Here is the is the program:
func main() {start := time.Now()fmt.Println(os.Args)fmt.Println(time.Since(start))}
And its output:
[A B C D E F G H I J K L M N O P] 124.009µs
Here is my for loop:
package mainimport ("fmt""os""time")func main() {start := time.Now()var s stringfor i:=0; i<len(os.Args); i++{s += os.Args[i] + " "}fmt.Println(s)fmt.Println(time.Since(start))}
with the following output:
/tmp/go-build994847456/b001/exe/main A B C D E F G H I J K L M N O P 25.71µs
I was expecting to have the built in function in the standard library to be faster.
Do slices make my code less efficient ?
Should I use for loops or standard library fmt.println?
I'm also confused how would the strings.Join(os.Args\[1:\], " ") performed 74.293µs
答案1
得分: 0
使用基准测试：
var slice = []string{"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P"}func BenchmarkFMT(b *testing.B) {b.ReportAllocs()for n := 0; n < b.N; n++ {_ = fmt.Sprint(slice)}}func BenchmarkStringConcat(b *testing.B) {b.ReportAllocs()for n := 0; n < b.N; n++ {var str stringfor _, s := range slice {str += s + " "}}}func BenchmarkStringsBuilder(b *testing.B) {b.ReportAllocs()for n := 0; n < b.N; n++ {var l intfor _, s := range slice {l += len(s)}var sb strings.Buildersb.Grow(l + len(slice)*len(" "))for _, s := range slice {sb.WriteString(s)sb.WriteString(" ")}_ = sb.String()}}func BenchmarkStringsJoin(b *testing.B) {b.ReportAllocs()for n := 0; n < b.N; n++ {_ = strings.Join(slice, " ")}}
BenchmarkFMTBenchmarkFMT-8 734088 1633 ns/op 616 B/op 34 allocs/opBenchmarkStringConcatBenchmarkStringConcat-8 1290666 919.1 ns/op 1200 B/op 32 allocs/opBenchmarkStringsBuilderBenchmarkStringsBuilder-8 6074888 198.6 ns/op 64 B/op 1 allocs/opBenchmarkStringsJoinBenchmarkStringsJoin-8 4941542 241.7 ns/op 64 B/op 1 allocs/opPASS
英文:
Use benchmarks:
var slice = []string{"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P"}func BenchmarkFMT(b *testing.B) {b.ReportAllocs()for n := 0; n < b.N; n++ {_ = fmt.Sprint(slice)}}func BenchmarkStringConcat(b *testing.B) {b.ReportAllocs()for n := 0; n < b.N; n++ {var str stringfor _, s := range slice {str += s + " "}}}func BenchmarkStringsBuilder(b *testing.B) {b.ReportAllocs()for n := 0; n < b.N; n++ {var l intfor _, s := range slice {l += len(s)}var sb strings.Buildersb.Grow(l + len(slice)*len(" "))for _, s := range slice {sb.WriteString(s)sb.WriteString(" ")}_ = sb.String()}}func BenchmarkStringsJoin(b *testing.B) {b.ReportAllocs()for n := 0; n < b.N; n++ {_ = strings.Join(slice, " ")}}
BenchmarkFMTBenchmarkFMT-8 734088 1633 ns/op 616 B/op 34 allocs/opBenchmarkStringConcatBenchmarkStringConcat-8 1290666 919.1 ns/op 1200 B/op 32 allocs/opBenchmarkStringsBuilderBenchmarkStringsBuilder-8 6074888 198.6 ns/op 64 B/op 1 allocs/opBenchmarkStringsJoinBenchmarkStringsJoin-8 4941542 241.7 ns/op 64 B/op 1 allocs/opPASS
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