array in golang

                                    // Sum function takes a pointer of array with 3 float numbers. if you define `a *[4]float64` then you get type error
func Sum(a *[3]float64) (sum float64) {
    for _, v := range *a {
        sum += v
    }
    return
}

array := [...]float64{7.0, 8.5, 9.1}
x := Sum(&array)  // Note the explicit address-of operator
/*
## Array in Golang
1. There are major differences between the ways arrays work in 
   Go and C. In Go:
	- Arrays are values. Assigning one array to another copies 
      all the elements.
	- In particular, if you pass an array to a function, it will 
      receive a copy of the array, not a pointer to it.
	- The size of an array is part of its type. The types [10]int
      and [20]int are distinct.
2. The value property can be useful but also expensive; if you 
   want C-like behavior and efficiency, you can pass a pointer 
   to the array.
*/

                                    var a [10]int // declare an int array with length 10. Array length is part of the type!
a[3] = 42     // set elements
i := a[3]     // read elements

// declare and initialize
var a = [2]int{1, 2}
a := [2]int{1, 2} //shorthand
a := [...]int{1, 2} // elipsis -> Compiler figures out array length

                                    package main

import (
	"fmt"
)

func main() {

	// array with not range maximal capacity
	arrayNotMax := [...]int{1991, 1992, 1993, 1994, 1995}

	// array with range maximal capacity
	var arrayMax [3]int
	arrayMax[0] = 1990
	arrayMax[1] = 1991
	arrayMax[2] = 1992

	// array using make method
	var arrayWithMake = make([]string, 3)
	arrayWithMake[0] = "zero"
	arrayWithMake[1] = "one"
	arrayWithMake[2] = "two"

	// array multi dimension
	var arrayMultiDimension = [2][5]int{{1, 2, 3, 4, 5}, {6, 7, 8, 9, 10}}

	fmt.Printf("read arrayNotMax value %#v \n", arrayNotMax)
	fmt.Printf("read arrayMax value %#v \n", arrayMax)
	fmt.Printf("read arrayWithMake value %#v \n", arrayWithMake)
	fmt.Println("read length of array", len(arrayNotMax))
	fmt.Println("read capacity of array", cap(arrayNotMax))
	fmt.Println("read arrayMultiDimension value", arrayMultiDimension)

}

                                    package main
import "fmt"

func main() {
	var x [5]int // An array of 5 integers

	x[0] = 100
	x[1] = 101
	x[3] = 103
	x[4] = 105

	fmt.Printf("x[0] = %d, x[1] = %d, x[2] = %d\n", x[0], x[1], x[2])
	fmt.Println("x = ", x)
}