Golang : Find commonalities in two slices or arrays example

Problem:

You have two slices of the same length and you want to find out if they have similar/common items.

Solution :

• Iterate items of the first slice.
• Get the index number.
• Use the index number to get the second slice item.
• Compare the items.
• If similar or common, then add the item to a new slice.
• Loop until no more item in the first slice.

Here you go!

 package main

 import (
 "fmt"
 )

 // NOTE : This example will only work if the length of slice a == length of slice b
 // In production, make sure to check the length and capacity of the slices
 // before comparing.

 func main() {

 a := []string{"Hello", "No", "Cheers"}

 fmt.Println("Slice a : ", a)

 b := []string{"Hello", "Yes", "Cheers"}
 fmt.Println("Slice b : ", b)

 // compare a to be and find common items
 // and store into c
 c := []string{}

 for i := range a {
 if a[i] == b[i] {
 c = append(c, a[i])
 }
 }

 fmt.Println("Common items : ", c)

 // compare a to be and find item not in a
 // and store into d
 d := []string{}

 for i := range a {
 if a[i] != b[i] {
 d = append(d, a[i])
 }
 }

 fmt.Println("Item that a has over b ", d)

 // compare a to be and find item not in b
 // and store into e
 e := []string{}

 for i := range b { // iterate b instead of a
 if a[i] != b[i] {
 e = append(e, b[i])
 }
 }

 fmt.Println("Item that b has over a ", e)

 }

Output :

Slice a : [Hello No Cheers]

Slice b : [Hello Yes Cheers]

Common items : [Hello Cheers]

Item that a has over b [No]

Item that b has over a [Yes]

NOTES: This example will only work if the length of slice a == length of slice b. In production, make sure to check the length and capacity of the slices before comparing.Otherwise, you will get panic: runtime error: index out of range error.

References :

https://blog.golang.org/slices