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第一个索引值。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.索引:该函数用于从原始字符串查找给定字符串的第一个实例的索引值。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 Index(str, sbstr string) int
这里, str是原始字符串, sbstr是我们要查找索引值的字符串。让我们借助一个例子来讨论这个概念:
例子:
// Go program to illustrate how to find
// the 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 index value of the given strings
// Using Index() function
res1 := strings.Index(str1, "Geeks")
res2 := strings.Index(str2, "do")
res3 := strings.Index(str3, "chess")
res4 := strings.Index("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: 32
Result 2: 3
Result 3: -1
Result 4: 3
2. IndexAny:此方法从原始字符串的字符返回任何Unicode 代码点的第一个实例的索引。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 IndexAny(str, charstr string) int
这里, str是原始字符串, charstr是来自我们要查找索引值的字符的 Unicode 代码点。
例子:
// Go program to illustrate how to find
// the 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 index value
// of the given strings
// Using IndexAny() function
res1 := strings.IndexAny(str1, "G")
res2 := strings.IndexAny(str2, "do")
res3 := strings.IndexAny(str3, "lqxa")
res4 := strings.IndexAny("GeeksforGeeks, geeks", "uywq")
// 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: 32
Result 2: 3
Result 3: 2
Result 4: -1
3. IndexByte:该函数返回原始字符串给定字节的第一个实例的索引。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 IndexByte(str string, b byte) int
这里, str是原始字符串, b是一个字节,我们要找到它的索引值。让我们借助一个例子来讨论这个概念:
例子:
// Go program to illustrate how to find
// the 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 index value of the given bytes
// Using IndexByte() function
res1 := strings.IndexByte(str1, 'c')
res2 := strings.IndexByte(str2, 'o')
res3 := strings.IndexByte(str3, 'q')
res4 := strings.IndexByte("GeeksforGeeks, geeks", 'G')
// 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: 3
Result 2: 4
Result 3: -1
Result 4: 0