In Go, an array is a numbered sequence of elements of a specific length.
In other words, an array is a collection of elements of a single data type. An array holds a fixed number of elements, and it cannot grow or shrink.
- Elements of an array are accessed through indexes.
- The first index is 0.
- By default, empty arrays are initialized with zero values (0, 0.0, false, or "").
Go - declare and initialize an array
The following example shows how to initialize an array in Go.
package main
import "fmt"
func main() {
var vals [2]int
fmt.Println(vals)
vals[0] = 1
vals[1] = 2
fmt.Println(vals)
}
Output:
[0 0] [1 2]
Use below syntax to declare and initialize an array in one line:
package main
import "fmt"
func main() {
b := [5]int{1, 2, 3, 4, 5}
fmt.Println("dcl:", b)
}
Output:
[1 2 3 4 5] [1 2 3 0 0]
Go - array literal
Golang has array literals; we can specify the elements of the array between {} brackets.
In the example, we define two arrays with array literals.
package main
import "fmt"
func main() {
vals := [5]int{1, 2, 3, 4, 5}
fmt.Println(vals)
vals2 := [5]int{1, 2, 3}
fmt.Println(vals2)
}
Output:
[1 2 3 4 5] [1 2 3 0 0]
Go - array length
The length of the array is determined with the len() function.
In the example, we define an array of strings. We print the number of programming languages in the array.
package main
import "fmt"
func main() {
progLangs := [5]string{ "C", "C++", "Java", "Python", "Go" }
fmt.Println("There are", len(progLangs ), "programming languages in the array")
}
Output:
[1 2 3 4 5] [1 2 3 0 0]
Go - array indexing
Arrays are accessed with their index.
package main
import "fmt"
func main() {
var progLangs[5]string
progLangs[0] = "C"
progLangs[1] = "C++"
progLangs[2] = "Java"
progLangs[3] = "Python"
progLangs[4] = "Go"
fmt.Println(progLangs[0], progLangs[1])
fmt.Println(progLangs)
}
Output:
C C++ [C C++ Java Python Go]