如何循環訪問切片并從輸出中生成新的單個字符串，然后在函數中返回該字符串？例如，如果我想讀取切片并為每個項目添加索引，則將新更改放在單個字符串中并在函數中返回：func buildString() string { strSlice := []string{"one", "two", "three"} for index, element := range strSlice{ fmt.Println(index, "===", element) bigString := append(strSlice, fmt.Prinln(index, "===", element) }return bigString}
2 回答
阿晨1998
TA貢獻2037條經驗 獲得超6個贊
我完全同意Marc的評論，但為了完整起見，以下是您嘗試完成的可能解決方案：
func buildString(strSlice []string) string {
var bigString string
for index, element := range strSlice {
bigString += fmt.Sprintf("%d === %s\n", index, element)
}
return bigString
}
func main() {
strSlice := []string{"one", "two", "three"}
result := buildString(strSlice)
fmt.Print(result)
}
但是，請參加馬克推薦給你的圍棋之旅。
楊魅力
TA貢獻1811條經驗 獲得超6個贊
您可以使用，這更有效，請嘗試以下操作：strings.Builder
func buildString(a []string) string {
var sb strings.Builder
for i, s := range a {
sb.WriteString(strconv.Itoa(i))
sb.WriteString(" === ")
sb.WriteString(s)
sb.WriteRune('\n')
}
return sb.String()
}
基準：
Benchmark1-8 4203799 252 ns/op 56 B/op 3 allocs/op
Benchmark6-8 5044305 280 ns/op 56 B/op 3 allocs/op
Benchmark4-8 4332459 319 ns/op 72 B/op 3 allocs/op
Benchmark5-8 2792514 371 ns/op 56 B/op 3 allocs/op
Benchmark3-8 1000000 1018 ns/op 144 B/op 8 allocs/op
Benchmark2-8 1000000 1109 ns/op 152 B/op 8 allocs/op
法典：
package main
import (
"fmt"
"strconv"
"strings"
"testing"
)
func buildString(a []string) string {
var sb strings.Builder
for i, s := range a {
sb.WriteString(strconv.Itoa(i))
sb.WriteString(" === ")
sb.WriteString(s)
sb.WriteRune('\n')
}
return sb.String()
}
func buildString6(a []string) string {
var sb strings.Builder
for i, s := range a {
sb.WriteString(strconv.Itoa(i))
sb.WriteString(" === ")
sb.WriteString(s)
sb.WriteString("\n")
}
return sb.String()
}
func buildString5(a []string) string {
var sb strings.Builder
for i, s := range a {
sb.WriteString(strconv.Itoa(i))
sb.WriteString(" === " + s + "\n")
}
return sb.String()
}
func buildString4(a []string) string {
var sb strings.Builder
b := make([]byte, 0, 10)
for i, s := range a {
b = strconv.AppendInt(b[:0], int64(i), 10)
b = append(b, " === "...)
b = append(b, s...)
b = append(b, '\n')
sb.WriteString(string(b))
}
return sb.String()
}
func buildString3(a []string) string {
var sb strings.Builder
for i, s := range a {
sb.WriteString(fmt.Sprintf("%d === %s\n", i, s))
}
return sb.String()
}
func buildString2(strSlice []string) string {
var bigString string
for index, element := range strSlice {
bigString += fmt.Sprintf("%d === %s\n", index, element)
}
return bigString
}
func Benchmark1(b *testing.B) {
strSlice := []string{"one", "two", "three"}
for i := 0; i < b.N; i++ {
_ = buildString(strSlice)
}
}
func Benchmark2(b *testing.B) {
strSlice := []string{"one", "two", "three"}
for i := 0; i < b.N; i++ {
_ = buildString2(strSlice)
}
}
func Benchmark3(b *testing.B) {
strSlice := []string{"one", "two", "three"}
for i := 0; i < b.N; i++ {
_ = buildString3(strSlice)
}
}
func Benchmark4(b *testing.B) {
strSlice := []string{"one", "two", "three"}
for i := 0; i < b.N; i++ {
_ = buildString4(strSlice)
}
}
func Benchmark5(b *testing.B) {
strSlice := []string{"one", "two", "three"}
for i := 0; i < b.N; i++ {
_ = buildString5(strSlice)
}
}
func Benchmark6(b *testing.B) {
strSlice := []string{"one", "two", "three"}
for i := 0; i < b.N; i++ {
_ = buildString6(strSlice)
}
}
go 版本 go1.17.1
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