Creating a Multiplication Table for a Number in Golang

The challenge

Your goal is to return multiplication table for number that is always an integer from 1 to 10.

For example, a multiplication table (string) for number == 5 looks like below:

1 * 5 = 5
2 * 5 = 10
3 * 5 = 15
4 * 5 = 20
5 * 5 = 25
6 * 5 = 30
7 * 5 = 35
8 * 5 = 40
9 * 5 = 45
10 * 5 = 50

P. S. You can use \n in string to jump to the next line.

Note: newlines should be added between rows, but there should be no trailing newline at the end.

The solution in Golang

Option 1:

package solution

import (
  "fmt"
  "strings"
)

func MultiTable(number int) string {
  superstring := ""
  for i := 1; i < 11; i++ {
    superstring += fmt.Sprintf("%d * %d = %d\n", i, number, number * i)
  }
  return strings.TrimRight(superstring, "\n")
}

Option 2:

package solution

import "fmt"

func MultiTable(number int) (res string) {
  for i := 1; i <= 10; i++ {
    res += fmt.Sprintf("%d * %d = %d\n", i, number, number*i)
  }
  return res[:len(res)-1]
}

Option 3:

package solution

import "fmt"
import "strings"

func MultiTable(number int) string {
  var s []string
  for i := 1; i <= 10; i++ {
    s = append(s, fmt.Sprintf("%d * %d = %d", i, number, i*number))
  }
  return strings.Join(s[:],"\n")
}

Test cases to validate our solution

package our_test

import (
  . "github.com/onsi/ginkgo"
  . "github.com/onsi/gomega"
)

var _ = Describe("Test MultiTable", func() {
   It("should handle basic cases", func() {
     Expect(MultiTable(5)).To(Equal("1 * 5 = 5\n2 * 5 = 10\n3 * 5 = 15\n4 * 5 = 20\n5 * 5 = 25\n6 * 5 = 30\n7 * 5 = 35\n8 * 5 = 40\n9 * 5 = 45\n10 * 5 = 50"))
     Expect(MultiTable(1)).To(Equal("1 * 1 = 1\n2 * 1 = 2\n3 * 1 = 3\n4 * 1 = 4\n5 * 1 = 5\n6 * 1 = 6\n7 * 1 = 7\n8 * 1 = 8\n9 * 1 = 9\n10 * 1 = 10"))
   })
})