Function main

go/language/slice.go:11–276

()

)

func main() {
	// ----------------------
	// Declare and initialize
	// ----------------------

	// Create a slice with a length of 5 elements.
	// make is a special built-in function that only works with slice, map and channel.
	// make creates a slice that has an array of 5 strings behind it. We are getting back a 3 word
	// data structure: the first word points to the backing array, second word is length and third
	// one is capacity.
	//  -----
	// |  *  | --> | nil | nil | nil | nil | nil |
	//  -----      |  0  |  0  |  0  |  0  |  0  |
	// |  5  |
	//  -----
	// |  5  |
	//  -----

	// ------------------
	// Length vs Capacity
	// ------------------

	// Length is the number of elements from this pointer position we have access to (read and write).
	// Capacity is the total number of elements from this pointer position that exist in the
	// backing array.

	// Syntactic sugar -> looks like array
	// It also have the same cost that we've seen in array.
	// One thing to be mindful about: there is no value in the bracket []string inside the make
	// function. With that in mind, we can constantly notice that we are dealing with a slice, not
	// array.
	slice1 := make([]string, 5)
	slice1[0] = "Apple"
	slice1[1] = "Orange"
	slice1[2] = "Banana"
	slice1[3] = "Grape"
	slice1[4] = "Plum"

	// We can't access an index of a slice beyond its length.
	// Error: panic: runtime error: index out of range
	// slice1[5] = "Runtime error"

	// We are passing the value of slice, not its address. So the Println function will have its
	// own copy of the slice.
	fmt.Printf("\n=> Printing a slice\n")
	fmt.Println(slice1)

	// --------------
	// Reference type
	// --------------

	// Create a slice with a length of 5 elements and a capacity of 8.
	// make allows us to adjust the capacity directly on construction of this initialization.
	// What we end up having now is a 3 word data structure where the first word points to an array
	// of 8 elements, length is 5 and capacity is 8.
	//  -----
	// |  *  | --> | nil | nil | nil | nil | nil | nil | nil | nil |
	//  -----      |  0  |  0  |  0  |  0  |  0  |  0  |  0  |  0  |