Función para concatenar un arreglo de ids usando bytes

main.go

package main

import (
	"bytes"
	"fmt"
)

func main() {
	ids := []string{"id 1", "id 2", "id 3", "id 4", "id 5"}
	fmt.Println(concatWithBuffer(ids))
}

func concatWithBuffer(ids []string) string {
	sentence := bytes.NewBufferString(fmt.Sprintf("[{ id: %s },", ids[0]))

	for _, value := range ids[1 : len(ids)-1] {
		sentence.WriteString(fmt.Sprintf("{ id: %s },", value))
	}

	sentence.WriteString(fmt.Sprintf("{ id: %s }]", ids[len(ids)-1]))

	return sentence.String()
}