Delete the last character of the string in golang

package main

import (
   	"fmt"
   	"strings"
)



func TrimSuffix(s, suffix string) string {
    

   	if strings.HasSuffix(s, suffix) {
    
   		s = s[:len(s)-len(suffix)]
   	}

   	return s
}



func main() {
    

   	s := "a string ++"
   	fmt.Println("s: ", s)

   	// Trim one trailing '+'.
   	s1 := s
   	if last := len(s1) - 1; last >= 0 && s1[last] == '+' {
    
   		s1 = s1[:last]
	}
   	fmt.Println("s1:", s1)

   	// Trim all trailing '+'.
   	s2 := s
   	s2 = strings.TrimRight(s2, "+")
   	fmt.Println("s2:", s2)

   	// Trim suffix "+".
   	s3 := s
   	s3 = TrimSuffix(s3, "+")
   	fmt.Println("s3:", s3)
   	
}


 Output ：

s:  a string ++

s1: a string +

s2: a string 

s3: a string +