In Go, arrays are designed to store multiple values of the same type within a single variable. This feature allows developers to work efficiently without the need for creating multiple variables for related data.
How to Declare Arrays
Arrays in Go can be declared using two primary methods:
- Using the
varkeyword:var arrayName = [length]dataType{values} // Fixed length var arrayName = [...]dataType{values} // Length inferred - Using shorthand with
:=:arrayName := [length]dataType{values} // Fixed length arrayName := [...]dataType{values} // Length inferred
Note: The length of an array is always fixed in Go. It can be explicitly stated as a number or inferred automatically by the compiler based on the number of values.
Examples of Arrays in Go
Example 1: Declaring Arrays with Fixed Length
package mainimport ("fmt")func main() { var motorcycleModels = [3]string{"Ducati", "Yamaha", "Honda"} brands := [4]string{"Suzuki", "Honda", "Yamaha", "Ducati"} fmt.Println(motorcycleModels) fmt.Println(brands)}Output:
[Ducati Yamaha Honda][Suzuki Honda Yamaha Ducati]Example 2: Declaring Arrays with Inferred Length
package mainimport ("fmt")func main() { var motorcycleModels = [...]string{"Ducati", "Yamaha", "Honda"} brands := [...]string{"Suzuki", "Honda", "Yamaha", "Ducati"} fmt.Println(motorcycleModels) fmt.Println(brands)}Output:
[Ducati Yamaha Honda][Suzuki Honda Yamaha Ducati]Example 3: Array of Integers
package mainimport ("fmt")func main() { var motorcycleYears = [5]int{2019, 2020, 2021, 2022, 2023} fmt.Println(motorcycleYears)}Output:
[2019 2020 2021 2022 2023]Accessing Array Elements
To access a specific element in an array, simply use its index. Array indexing begins at 0.
Example:
package mainimport ("fmt")func main() { prices := [3]int{25000, 30000, 35000} fmt.Println(prices[0]) // Access first element fmt.Println(prices[2]) // Access third element}Output:
2500035000Modifying Array Elements
It is also possible to change an element within an array by referring to its index.
Example:
package mainimport ("fmt")func main() { prices := [3]int{25000, 30000, 35000} prices[2] = 40000 // Modify the third element fmt.Println(prices)}Output:
[25000 30000 40000]Array Initialization Defaults
When an array or one of its elements is not explicitly initialized, Go assigns a default value based on the data type. For example, the default for integers is 0, and for strings, it is "".
Example:
package mainimport ("fmt")func main() { brands := [5]string{} // Default initialization years := [5]int{2020, 2021} // Partially initialized models := [5]string{"Ducati", "Yamaha", "Honda", "Suzuki", "BMW"} // Fully initialized fmt.Println(brands) fmt.Println(years) fmt.Println(models)}Output:
["" "" "" "" ""][2020 2021 0 0 0][Ducati Yamaha Honda Suzuki BMW]Initializing Specific Elements Only
Go allows you to initialize specific elements in an array by specifying index-value pairs.
Example:
package mainimport ("fmt")func main() { years := [5]int{2:2018, 4:2020} // Initialize specific elements fmt.Println(years)}Output:
[0 0 2018 0 2020]Finding the Array Length
The len() function is available to calculate the length of an array.
Example:
package mainimport ("fmt")func main() { motorcycleBrands := [4]string{"Ducati", "Yamaha", "Honda", "Suzuki"} releaseYears := [...]int{2018, 2019, 2020, 2021, 2022} fmt.Println(len(motorcycleBrands)) fmt.Println(len(releaseYears))}Output:
45