Challenge 3 — Solution

Task: Create a map inventory of at least 4 items with int
quantities. Use a for...range loop to print each item with its
quantity, and keep a running total using a plain variable, printing
the total at the end. Then delete one item and print the map again
to confirm it's gone.

package main

import "fmt"

func main() {
	inventory := map[string]int{
		"apples":  10,
		"bananas": 5,
		"oranges": 8,
		"grapes":  12,
	}

	total := 0
	for item, quantity := range inventory {
		fmt.Println(item, ":", quantity)
		total += quantity
	}
	fmt.Println("Total:", total)

	delete(inventory, "bananas")
	fmt.Println(inventory)
}


Expected output (item order during the loop may vary):

apples : 10
bananas : 5
oranges : 8
grapes : 12
Total: 35
map[apples:10 grapes:12 oranges:8]

Notes:
- The order items print DURING the for...range loop is not
  guaranteed and can vary between runs — only the final Total (35)
  and the post-delete map contents are guaranteed, since the map's
  default Println formatting always sorts keys alphabetically.
- delete(inventory, "bananas") removes the key entirely — the final
  printed map has only 3 entries, with no trace of "bananas" left
  behind (not even as a zero value).
- total += quantity accumulates exactly the same way Chapter 6's
  slice-based running total did, just driven by a map's values
  instead of a slice's elements.