control_structure_idiom_4.go

package main

import "fmt"

func main() {
	var m = map[string]int{
		"tony": 21,
		"tom":  22,
		"jim":  23,
	}

	for k, v := range m {
		fmt.Println(k, v)
	}
	fmt.Println("\n")

	counter := 0
	for k, v := range m {
		if counter == 0 {
			delete(m, "tony")
		}
		counter++
		fmt.Println(k, v)
	}
	fmt.Println("counter is ", counter)
	fmt.Println("\n")

	m["tony"] = 21
	counter = 0

	for k, v := range m {
		if counter == 0 {
			m["lucy"] = 24
		}
		counter++
		fmt.Println(k, v)
	}
	fmt.Println("counter is ", counter)
}