add: unfinished code. people are having problems

15-slices/06-slice-expressions/02-examples/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"fmt"
+
+	s "github.com/inancgumus/prettyslice"
+)
+
+func main() {
+	// 1. slicing creates a new slice
+	nums := []int{1, 3, 5, 2, 4, 8}
+	odds := nums[:3]
+	evens := nums[3:]
+
+	// 2. backing array is shared
+	nums[1], nums[3] = 9, 6
+	s.Show("nums", nums)
+	s.Show("odds : nums[:3]", odds)
+	s.Show("evens: nums[3:]", evens)
+
+	// 3. you can create a new slice from an array
+	heyArr := [3]byte{'h', 'e', 'y'}
+	hey, he := heyArr[:], heyArr[:2]
+
+	// 4. sliced array will be shared among the slices
+	heyArr[0] = 'm'
+	s.Show("hey := heyArr[:]", hey)
+	s.Show("he  := heyArr[:2]", he)
+
+	// 5. index expression returns a value
+	//    while a slice expression returns a slice
+	s.Show("nums[0]", nums[0])
+	s.Show("nums[0:1]", nums[0:1])
+	fmt.Printf("nums[0]  : %T\n", nums[0])   // just int
+	fmt.Printf("nums[0:1]: %T\n", nums[0:1]) // []int slice
+
+	// 6. extending a slice up to its capacity
+	first := nums[0:1]
+	s.Show("first := nums[0:1]", first)
+	s.Show("first[0:2]", first[0:2])
+	s.Show("first[0:3]", first[0:3])
+	s.Show("first[0:4]", first[0:4])
+	s.Show("first[0:5]", first[0:5])
+	s.Show("first[0:6]", first[0:6])
+	// s.Show("first[0:7]", first[0:7]) // <- you can't
+
+	first = append(first[0:6], 9)
+	s.Show("first: with a new backing array", first)
+}