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,您可以使用以下函数从原始字符串找到指定字符串的最后一个索引值。这些函数是在字符串包下定义的,因此您必须在程序中导入字符串包才能访问这些函数:
1. LastIndex:该函数用于从原始字符串查找给定字符串的最后一个实例的索引值。如果给定的字符串在原始字符串不可用,则此方法将返回 -1。
句法:
func LastIndex(str, sbstr string) int
这里, str是原始字符串, sbstr是一个字符串,我们要找到最后一个索引值。
例子:
// Go program to illustrate how to find
// the last index value of the given string
package main
import (
"fmt"
"strings"
)
// Main function
func main() {
// Creating and initializing the strings
str1 := "Welcome to the online portal of GeeksforGeeks"
str2 := "My dog name is Dollar"
str3 := "I like to play Ludo"
// Displaying strings
fmt.Println("String 1: ", str1)
fmt.Println("String 2: ", str2)
fmt.Println("String 3: ", str3)
// Finding the last index value of the given string
// Using LastIndex() function
res1 := strings.LastIndex(str1, "e")
res2 := strings.LastIndex(str2, "do")
res3 := strings.LastIndex(str3, "jk")
res4 := strings.LastIndex("GeeksforGeeks, geeks", "ks")
// Displaying the result
fmt.Println("\nIndex values:")
fmt.Println("Result 1: ", res1)
fmt.Println("Result 2: ", res2)
fmt.Println("Result 3: ", res3)
fmt.Println("Result 4: ", res4)
}
输出:
String 1: Welcome to the online portal of GeeksforGeeks
String 2: My dog name is Dollar
String 3: I like to play Ludo
Index values:
Result 1: 42
Result 2: 3
Result 3: -1
Result 4: 18
2. LastIndexAny:此方法从原始字符串的字符返回任何Unicode代码点的最后一个实例的索引。如果来自 chars 的 Unicode 代码点在原始字符串不可用,则此方法将返回 -1。
句法:
func LastIndexAny(str, charstr string) int
这里, str是原始字符串, charstr是来自我们要查找最后一个索引值的字符的 Unicode 代码点。
例子:
// Go program to illustrate how to find the
// last index value of the given string
package main
import (
"fmt"
"strings"
)
// Main function
func main() {
// Creating and initializing the strings
str1 := "Welcome to the online portal of GeeksforGeeks"
str2 := "My dog name is Dollar"
str3 := "I like to play Ludo"
// Displaying strings
fmt.Println("String 1: ", str1)
fmt.Println("String 2: ", str2)
fmt.Println("String 3: ", str3)
// Finding the last index value of the given string
// Using LastIndexAny() function
res1 := strings.LastIndexAny(str1, "mewdv")
res2 := strings.LastIndexAny(str2, "ll")
res3 := strings.LastIndexAny(str3, "qzmj")
res4 := strings.LastIndexAny("GeeksforGeeks, geeks", "ee")
// Displaying the result
fmt.Println("\nIndex values:")
fmt.Println("Result 1: ", res1)
fmt.Println("Result 2: ", res2)
fmt.Println("Result 3: ", res3)
fmt.Println("Result 4: ", res4)
}
输出:
String 1: Welcome to the online portal of GeeksforGeeks
String 2: My dog name is Dollar
String 3: I like to play Ludo
Index values:
Result 1: 42
Result 2: 18
Result 3: -1
Result 4: 17
3. LastIndexByte:该函数返回原始字符串给定字节的最后一个实例的索引。如果给定的字节在原始字符串不可用,则此方法将返回 -1。
句法:
func LastIndexByte(str string, b byte) int
这里, str是原始字符串, b是一个字节,我们要找到它的最后一个索引值。
例子:
// Go program to illustrate how to find the
// last index value of the given bytes
package main
import (
"fmt"
"strings"
)
// Main function
func main() {
// Creating and initializing the strings
str1 := "Welcome to the online portal of GeeksforGeeks"
str2 := "My dog name is Dollar"
str3 := "I like to play Ludo"
// Displaying strings
fmt.Println("String 1: ", str1)
fmt.Println("String 2: ", str2)
fmt.Println("String 3: ", str3)
// Finding the last index value of the given bytes
// Using LastIndexByte() function
res1 := strings.LastIndexByte(str1, 'e')
res2 := strings.LastIndexByte(str2, 'a')
res3 := strings.LastIndexByte(str3, 'q')
res4 := strings.LastIndexByte("GeeksforGeeks, geeks", 's')
// Displaying the result
fmt.Println("\nIndex values:")
fmt.Println("Result 1: ", res1)
fmt.Println("Result 2: ", res2)
fmt.Println("Result 3: ", res3)
fmt.Println("Result 4: ", res4)
}
输出:
String 1: Welcome to the online portal of GeeksforGeeks
String 2: My dog name is Dollar
String 3: I like to play Ludo
Index values:
Result 1: 42
Result 2: 19
Result 3: -1
Result 4: 19