Arrays and Slices

Let's learn about Go's arrays and slices

Arrays

• In Go, when creating an array, you must specify the length of that array

  • ex)

    package main
    
    import "fmt"
    
    func main() {
     names := [5]string{"chloe", "camila", "bella"}
     names[3] = "charlotte"
     names[4] = "bree"
     fmt.Print(names)
    }

    • Go's index starts from 0, so in the above example, names[4] is the 5th index

  • If you put an index larger than the specified length when creating an array, an error will occur

Slices

• Sometimes you want to limit the size of an array, but sometimes you want to add elements without size limitation

  • The data type you can use in such cases is slice

• Slice in Go is an array but without length

  • ex)

    package main
    
    import "fmt"
    
    func main() {
     states := []string{"Florida", "Kentucky"}
     fmt.Println(states)
    }

    • The only difference from array is that there's no length

append()

• When adding items to a slice, use the append() function

• append() takes two arguments:

  1. slice

  2. value

• However, append() does not modify the slice

  • append() returns a slice with new values added!

    • So you need to update the slice again

    • ex)

      package main
      
      import "fmt"
      
      func main() {
       states := []string{"Florida", "Kentucky"}
       states = append(states, "California")
       fmt.Println(states)
      }

I think I'll probably use slice most of the time!