Overview

In GO string are UTF-8 encoded. strings package of GO provides a LastIndex method that can be used to get the index of the last occurrence of a substring in a particular string. It returns -1 is the substring is not present in the given string.

Below is the signature of the function

func LastIndex(s, substr string) int

Let’s look at the working code

Code:

package main
import (
"fmt"
"strings"
)
func main() {
//Output will be 1 as "bc" is present in "abcdef" at index 1
res := strings.LastIndex("abcdef", "bc")
fmt.Println(res)
//Output will be 8 as "cd" is present in "abcdefabcdef" at index 8
res = strings.LastIndex("abcdefabcdef", "cd")
fmt.Println(res)
//Output will be -1 as "ba" is not present in "abcdef"
res = strings.LastIndex("abcdef", "ba")
fmt.Println(res)
}

Output:

1
8
-1