package main
import (
"fmt"
"strings"
)
func main() {
var str string = "This is an example of a string"
fmt.Printf("T/F? Does the string \"%s\" have prefix %s? ", str, "Th")
fmt.Printf("%t\n", strings.HasPrefix(str, "Th"))
}
输出：
T/F? Does the string "This is an example of a string" have prefix Th? true
这个例子同样演示了转义字符 \ 和格式化字符串的使用。
4.7.2 字符串包含关系
Contains 判断字符串 s 是否包含 substr：
strings.Contains(s, substr string) bool
4.7.3 判断子字符串或字符在父字符串中出现的位置（索引）
Index 返回字符串 str 在字符串 s 中的索引（str 的第一个字符的索引），-1 表示字符串 s 不包含字符串 str：
strings.Index(s, str string) int
LastIndex 返回字符串 str 在字符串 s 中最后出现位置的索引（str 的第一个字符的索引），-1 表示字符串 s 不包含字符串 str：
strings.LastIndex(s, str string) int
如果 ch 是非 ASCII 编码的字符，建议使用以下函数来对字符进行定位：
strings.IndexRune(s string, r rune) int
package main
import (
"fmt"
"strings"
)
func main() {
var str string = "Hi, I'm Marc, Hi."
fmt.Printf("The position of \"Marc\" is: ")
fmt.Printf("%d\n", strings.Index(str, "Marc"))
fmt.Printf("The position of the first instance of \"Hi\" is: ")
fmt.Printf("%d\n", strings.Index(str, "Hi"))
fmt.Printf("The position of the last instance of \"Hi\" is: ")
fmt.Printf("%d\n", strings.LastIndex(str, "Hi"))
fmt.Printf("The position of \"Burger\" is: ")
fmt.Printf("%d\n", strings.Index(str, "Burger"))
}
输出：
The position of "Marc" is: 8
The position of the first instance of "Hi" is: 0
The position of the last instance of "Hi" is: 14
The position of "Burger" is: -1
4.7.4 字符串替换
Replace 用于将字符串 str 中的前 n 个字符串 old 替换为字符串 new，并返回一个新的字符串，如果 n = -1 则替换所有字符串 old 为字符串 new：
strings.Replace(str, old, new, n) string
4.7.5 统计字符串出现次数
Count 用于计算字符串 str 在字符串 s 中出现的非重叠次数：
strings.Count(s, str string) int
package main
import (
"fmt"
"strings"
)
func main() {
var str string = "Hello, how is it going, Hugo?"
var manyG = "gggggggggg"
fmt.Printf("Number of H's in %s is: ", str)
fmt.Printf("%d\n", strings.Count(str, "H"))
fmt.Printf("Number of double g's in %s is: ", manyG)
fmt.Printf("%d\n", strings.Count(manyG, "gg"))
}
输出：
Number of H's in Hello, how is it going, Hugo? is: 2
Number of double g’s in gggggggggg is: 5
4.7.6 重复字符串
Repeat 用于重复 count 次字符串 s 并返回一个新的字符串：
strings.Repeat(s, count int) string
package main
import (
"fmt"
"strings"
)
func main() {
var origS string = "Hi there! "
var newS string
newS = strings.Repeat(origS, 3)
fmt.Printf("The new repeated string is: %s\n", newS)
}
输出：
The new repeated string is: Hi there! Hi there! Hi there!
4.7.7 修改字符串大小写
ToLower 将字符串中的 Unicode 字符全部转换为相应的小写字符：
strings.ToLower(s) string
ToUpper 将字符串中的 Unicode 字符全部转换为相应的大写字符：
strings.ToUpper(s) string
package main
import (
"fmt"
"strings"
)
func main() {
var orig string = "Hey, how are you George?"
var lower string
var upper string
fmt.Printf("The original string is: %s\n", orig)
lower = strings.ToLower(orig)
fmt.Printf("The lowercase string is: %s\n", lower)
upper = strings.ToUpper(orig)
fmt.Printf("The uppercase string is: %s\n", upper)
}
输出：
The original string is: Hey, how are you George?
The lowercase string is: hey, how are you george?
The uppercase string is: HEY, HOW ARE YOU GEORGE?
package main
import (
"fmt"
"strings"
)
func main() {
str := "The quick brown fox jumps over the lazy dog"
sl := strings.Fields(str)
fmt.Printf("Splitted in slice: %v\n", sl)
for _, val := range sl {
fmt.Printf("%s - ", val)
}
fmt.Println()
str2 := "GO1|The ABC of Go|25"
sl2 := strings.Split(str2, "|")
fmt.Printf("Splitted in slice: %v\n", sl2)
for _, val := range sl2 {
fmt.Printf("%s - ", val)
}
fmt.Println()
str3 := strings.Join(sl2,";")
fmt.Printf("sl2 joined by ;: %s\n", str3)
}
输出：
Splitted in slice: [The quick brown fox jumps over the lazy dog]
The - quick - brown - fox - jumps - over - the - lazy - dog -
Splitted in slice: [GO1 The ABC of Go 25]
GO1 - The ABC of Go - 25 -
sl2 joined by ;: GO1;The ABC of Go;25
package main
import (
"fmt"
"strconv"
)
func main() {
var orig string = "666"
var an int
var newS string
fmt.Printf("The size of ints is: %d\n", strconv.IntSize)
an, _ = strconv.Atoi(orig)
fmt.Printf("The integer is: %d\n", an)
an = an + 5
newS = strconv.Itoa(an)
fmt.Printf("The new string is: %s\n", newS)
}
输出：
64 位系统：
The size of ints is: 64
32 位系统：
The size of ints is: 32
The integer is: 666
The new string is: 671
