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C # tutorial
Arrays are used to store multiple values of the same type in a single variable, instead of declaring separate variables for each value
Arrays are used to store multiple values of the same type in a single variable, instead of declaring separate variables for each value.
In Go, there are two ways to declare an array:
1. With the var
keyword:
var array_name = [length]datatype{values} // here length is defined
or
var array_name = [...]datatype{values} // here length is inferred
2. With the :=
sign:
array_name := [length]datatype{values} // here length
is defined
or
array_name := [...]datatype{values} //
here length is inferred
Note: The length specifies the number of elements to store in the array. In Go, arrays have a fixed length. The length of the array is either defined by a number or is inferred (means that the compiler decides the length of the array, based on the number of values).
This example declares two arrays (arr1 and arr2) with defined lengths:
package main
import ("fmt")
func main() {
var arr1 = [3]int{1,2,3}
arr2 := [5]int{4,5,6,7,8}
fmt.Println(arr1)
fmt.Println(arr2)
}
Result:
[1 2 3]
[4 5 6 7 8]
This example declares two arrays (arr1 and arr2) with inferred lengths:
package main
import ("fmt")
func main() {
var arr1 = [...]int{1,2,3}
arr2 := [...]int{4,5,6,7,8}
fmt.Println(arr1)
fmt.Println(arr2)
}
Result:
[1 2 3]
[4 5 6 7 8]
This example declares an array of strings:
package main
import ("fmt")
func main() {
var cars = [4]string{"Volvo", "BMW", "Ford", "Mazda"}
fmt.Print(cars)
}
Result:
[Volvo BMW Ford Mazda]
You can access a specific array element by referring to the index number.
In Go, array indexes start at 0. That means that [0] is the first element, [1] is the second element, etc.
This example shows how to access the first and third elements in the prices array:
package main
import ("fmt")
func main() {
prices := [3]int{10,20,30}
fmt.Println(prices[0])
fmt.Println(prices[2])
}
Result:
10
30
You can also change the value of a specific array element by referring to the index number.
This example shows how to change the value of the third element in the prices array:
package main
import ("fmt")
func main() {
prices := [3]int{10,20,30}
prices[2] = 50
fmt.Println(prices)
}
Result:
[10 20 50]
If an array or one of its elements has not been initialized in the code, it is assigned the default value of its type.
package main
import ("fmt")
func main() {
arr1 := [5]int{} //not initialized
arr2 := [5]int{1,2} //partially initialized
arr3 := [5]int{1,2,3,4,5} //fully initialized
fmt.Println(arr1)
fmt.Println(arr2)
fmt.Println(arr3)
}
Result:
[0 0 0 0 0]
[1 2 0 0 0]
[1 2 3 4 5]
It is possible to initialize only specific elements in an array.
This example initializes only the second and third elements of the array:
package main
import ("fmt")
func main() {
arr1 := [5]int{1:10,2:40}
fmt.Println(arr1)
}
Result:
[0 10 40 0 0]
Example Explained
The array above has 5 elements.
1:10
means: assign
10
to array index 1
(second element).2:40
means: assign 40
to
array index
2
(third element).The len()
function is used to find the length of an array:
package main
import ("fmt")
func main() {
arr1 := [4]string{"Volvo", "BMW", "Ford", "Mazda"}
arr2 := [...]int{1,2,3,4,5,6}
fmt.Println(len(arr1))
fmt.Println(len(arr2))
}
Result:
4
6