golang strconv 包使用
strconv 官方文件
https://godoc.org/strconv
strconv 包實現了 基本資料型別的字串 的轉換。
匯入包
import "strconv"
數字轉換
Atoi - string到int
Itoa - int到string
package main import ( "fmt" "reflect" "strconv" ) func main() { i, err := strconv.Atoi("-42") fmt.Println(reflect.TypeOf(i).String(), i, err) s := strconv.Itoa(-42) fmt.Println(reflect.TypeOf(s).String(), s) }
執行結果：
int -42 <nil>
string -42
Quote、QuoteRune、QuoteRuneToASCII、QuoteToASCII
package main import ( "fmt" "strconv" ) func main() { s := strconv.Quote(`"Fran & Freddie's Diner ☺"`) fmt.Printf("%T, %v\n", s, s) s = strconv.QuoteRune('☺') fmt.Printf("%T, %v\n", s, s) s = strconv.QuoteRuneToASCII('☺') fmt.Printf("%T, %v\n", s, s) s = strconv.QuoteToASCII(`"Fran & Freddie's Diner ☺"`) fmt.Printf("%T, %v\n", s, s) }
執行結果：
string, "\"Fran & Freddie's Diner\t☺\""
string, '☺'
string, '\u263a'
string, "\"Fran & Freddie's Diner\t\u263a\""
ParseBool, ParseFloat, ParseInt, and ParseUint 轉化字串到值
package main import ( "fmt" "reflect" "strconv" ) func main() { b, err := strconv.ParseBool("true") fmt.Println(reflect.TypeOf(b).String(), b, err) f, err := strconv.ParseFloat("3.1415", 64) fmt.Println(reflect.TypeOf(f).String(), f, err) i, err := strconv.ParseInt("-42", 10, 64) fmt.Println(reflect.TypeOf(i).String(), i, err) u, err := strconv.ParseUint("42", 10, 64) fmt.Println(reflect.TypeOf(u).String(), u, err) }
執行結果：
bool true <nil>
float64 3.1415 <nil>
int64 -42 <nil>
uint64 42 <nil>
FormatBool, FormatFloat, FormatInt, and FormatUint 轉化值到字串
package main
import (
"fmt"
"reflect"
"strconv"
)
func main() {
s := strconv.FormatBool(true)
fmt.Println(reflect.TypeOf(s).String(), s)
s = strconv.FormatFloat(3.1415, 'E', -1, 64)
fmt.Println(reflect.TypeOf(s).String(), s)
s = strconv.FormatInt(-42, 16)
fmt.Println(reflect.TypeOf(s).String(), s)
s = strconv.FormatUint(42, 16) // 42 = 0x2A
fmt.Println(reflect.TypeOf(s).String(), s)
}執行結果：
string true
string 3.1415E+00
string -2a
string 2a
AppendBool, AppendFloat, AppendInt, and AppendUint 格式化值到切片
package main
import (
"fmt"
"strconv"
)
func main() {
// 將 true 追加到 b
b := []byte("bool:")
b = strconv.AppendBool(b, true)
fmt.Println(b)
fmt.Println(string(b))
b32 := []byte("float32:")
b32 = strconv.AppendFloat(b32, 3.1415926535, 'E', -1, 32)
fmt.Println(string(b32))
b64 := []byte("float64:")
b64 = strconv.AppendFloat(b64, 3.1415926535, 'E', -1, 64)
fmt.Println(string(b64))
b10 := []byte("int (base 10):")
b10 = strconv.AppendInt(b10, -42, 10)
fmt.Println(string(b10))
b16 := []byte("int (base 16):")
b16 = strconv.AppendInt(b16, -42, 16)
fmt.Println(string(b16))
}執行結果：
[98 111 111 108 58 116 114 117 101]
bool:true
float32:3.1415927E+00
float64:3.1415926535E+00
int (base 10):-42
int (base 16):-2a
AppendQuote, AppendQuoteRune, AppendQuoteRuneToASCII, and AppendUint 格式化值到切片
package main
import (
"fmt"
"strconv"
)
func main() {
b := []byte("quote:")
b = strconv.AppendQuote(b, `"Fran & Freddie's Diner"`)
fmt.Println(string(b))
}執行結果：
quote:"\"Fran & Freddie's Diner\""
package main
import (
"fmt"
"strconv"
)
func main() {
// 符文
b := []byte("rune:")
b = strconv.AppendQuoteRune(b, '☺')
fmt.Println(string(b))
}執行結果：
rune:'☺'
package main
import (
"fmt"
"strconv"
)
func main() {
b := []byte("rune (ascii):")
b = strconv.AppendQuoteRuneToASCII(b, '☺')
fmt.Println(string(b))
}執行結果：
rune (ascii):'\u263a'
package main
import (
"fmt"
"strconv"
)
func main() {
b10 := []byte("uint (base 10):")
b10 = strconv.AppendUint(b10, 42, 10)
fmt.Println(string(b10))
b16 := []byte("uint (base 16):")
b16 = strconv.AppendUint(b16, 42, 16)
fmt.Println(string(b16))
}執行結果：
uint (base 10):42
uint (base 16):2a