Go – Array Functions

In Go, arrays are fixed-size collections of elements of the same type. You can use functions to perform operations on arrays, such as iterating, updating, or performing calculations. Functions can accept arrays as arguments, return arrays, or modify array elements.

In this tutorial, we will explore how to create and use functions for working with arrays in Go, with practical examples and detailed explanations.

Syntax for Array Functions

The syntax to define a function that works with arrays is:

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func functionName(array [length]elementType) returnType {
    // Function body
}

Here:

  • functionName: The name of the function.
  • array: The parameter representing the array passed to the function.
  • length: The fixed size of the array.
  • elementType: The type of elements in the array (e.g., int, float64, etc.).
  • returnType: The type of the value returned by the function.

Examples of Array Functions

1. Function to Print Array Elements

This function takes an array as input and prints its elements:

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package main

import "fmt"

// Function to print array elements
func printArray(arr [5]int) {
    for i, v := range arr {
        fmt.Printf("Element at index %d: %d\n", i, v)
    }
}

func main() {
    // Declare and initialize an array
    numbers := [5]int{10, 20, 30, 40, 50}

    // Call the function
    printArray(numbers)
}

Explanation

  1. Define Function: The function printArray accepts an array of 5 integers as input.
  2. Iterate and Print: A for loop with range is used to iterate through the array and print each element.
  3. Call Function: The array numbers is passed to the function for printing.

Output

2. Function to Find the Sum of Array Elements

This function calculates the sum of all elements in an array:

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package main

import "fmt"

// Function to calculate the sum of array elements
func sumArray(arr [5]int) int {
    sum := 0
    for _, v := range arr {
        sum += v
    }
    return sum
}

func main() {
    // Declare and initialize an array
    numbers := [5]int{10, 20, 30, 40, 50}

    // Call the function and print the result
    fmt.Println("Sum of array elements:", sumArray(numbers))
}

Explanation

  1. Define Function: The function sumArray accepts an array of 5 integers and returns their sum.
  2. Iterate and Sum: A for loop with range iterates through the array, adding each element to sum.
  3. Return Result: The sum is returned and printed in the main function.

Output

3. Function to Reverse an Array

This function reverses the order of elements in an array:

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package main

import "fmt"

// Function to reverse an array
func reverseArray(arr [5]int) [5]int {
    var reversed [5]int
    for i, v := range arr {
        reversed[len(arr)-1-i] = v
    }
    return reversed
}

func main() {
    // Declare and initialize an array
    numbers := [5]int{10, 20, 30, 40, 50}

    // Call the function and print the result
    fmt.Println("Reversed Array:", reverseArray(numbers))
}

Explanation

  1. Define Function: The function reverseArray accepts an array of 5 integers and returns a reversed array.
  2. Reverse Logic: A for loop assigns elements from the input array to the reversed array in reverse order.
  3. Return Result: The reversed array is returned and printed in the main function.

Output

Points to Remember

  • Fixed Size: Arrays passed to functions must have a fixed size matching the parameter definition.
  • Pass by Value: Arrays in Go are passed by value, meaning the original array is not modified unless a pointer is used.
  • Return Types: Functions can return arrays, which can be assigned to variables or directly used.
  • Utility: Array functions are useful for modularizing repetitive tasks, such as calculations and transformations.