在 Go 语言中,字符串不同于Java、C++、 Python等其他语言。它是一系列可变宽度字符,其中每个字符都由一个或多个使用 UTF-8 编码的字节表示。
在 Go字符串,您还可以使用IndexRune()函数找到给定字符串指定符文的第一个索引。此函数返回 Unicode 代码点的第一个实例的索引,即指定的符文,如果指定的符文不存在于给定的字符串,则返回 -1。如果符文是utf8.RuneError ,则它返回任何无效 UTF-8 字节序列的第一个实例。它定义在字符串包下,因此您必须在程序中导入字符串包才能访问 IndexRune函数。
句法:
func IndexRune(str string, r rune) int
示例 1:
// Go program to illustrate how to find
// the index value of the given rune
package main
import (
"fmt"
"strings"
)
func main() {
// Creating and Finding the first index
// of the rune in the given string
// Using IndexRunefunction
res1 := strings.IndexRune("****Welcome to GeeksforGeeks****", 60)
res2 := strings.IndexRune("Learning how to trim"+
" a slice of bytes", 'r')
res3 := strings.IndexRune("GeeksforGeeks", 'G')
// Display the results
fmt.Println("Index Value 1: ", res1)
fmt.Println("Index Value 2: ", res2)
fmt.Println("Index Value 3: ", res3)
}
输出:
Index Value 1: -1
Index Value 2: 3
Index Value 3: 0
示例 2:
// Go program to illustrate how to find
// the index value of the given rune
package main
import (
"fmt"
"strings"
)
func main() {
// Creating and initializing a string
// Using shorthand declaration
string_1 := "Welcome to GeeksforGeeks"
string_2 := "AppleAppleAppleAppleAppleApple"
string_3 := "%G%E%E%K%S"
// Creating and initializing rune
var r1, r2, r3 rune
r1 = 'R'
r2 = 'l'
r3 = 42
// Finding the first index
// of the given rune
// Using IndexRune function
res1 := strings.IndexRune(string_1, r1)
res2 := strings.IndexRune(string_2, r2)
res3 := strings.IndexRune(string_3, r3)
// Display the results
fmt.Printf("String 1: %s , Rune 1:%q , Index Value: %d",
string_1, r1, res1)
fmt.Printf("\nString 2: %s , Rune 2:%q , Index Value: %d",
string_2, r2, res2)
fmt.Printf("\nString 3: %s , Rune 3:%q , Index Value: %d",
string_3, r3, res3)
}
输出:
String 1: Welcome to GeeksforGeeks , Rune 1:'R' , Index Value: -1
String 2: AppleAppleAppleAppleAppleApple , Rune 2:'l' , Index Value: 3
String 3: %G%E%E%K%S , Rune 3:'*' , Index Value: -1