Go Arrays: A Fixed-Size Collection

Arrays in Go provide a way to store multiple values of the same data type in a single variable. Unlike some other languages, Go arrays have a fixed size, meaning their length cannot be changed after creation.

Declaring and Initializing Arrays

There are two primary ways to declare an array in Go:

Using the var Keyword

Syntax
var arrayName [length]dataType

Explanation:

  • arrayName: The name of the array.
  • length: The number of elements the array can hold.
  • dataType: The data type of the elements in the array.

Example:

Code Snippet
var numbers [5]int // An array of 5 integers
Output
None

You can also initialize an array during declaration:

Code Snippet
var fruits [3]string = ["apple", "banana", "orange"]
Output
None

Using Short Declaration (:=)

Syntax
arrayName := [length]dataType{values}

Explanation:

  • arrayName: The name of the array.
  • length: The number of elements the array can hold.
  • dataType: The data type of the elements in the array.
  • values: Optional list of initial values.

Example:

Code Snippet
colors := [4]string{"red", "green", "blue", "yellow"}
Output
None

Array Length and Accessing Elements

Array Length

Use the len() function to get the number of elements in an array.

Code Snippet
length := len(numbers)
Output
None

Accessing Elements

Use an index (starting from 0) to access individual elements.

Code Snippet
firstElement := numbers[0]
Output
None

Modifying Array Elements

You can change the value of an element by assigning a new value to its index:

Code Snippet
numbers[2] = 15
Output
None

Iterating Over Arrays

Use a for loop to iterate through all elements of an array:

Code Snippet
for i := 0; i < len(numbers); i++ {
    fmt.Println(numbers[i])
}
Output
None

Key Points to Remember

  • Arrays have a fixed size.
  • Array elements are accessed using indices starting from 0.
  • Arrays are value types, meaning assigning an array to another variable creates a copy.