Working with maps in Golang

working_with_maps.go

package main

import "fmt"

func main() {

	var mscores = make(map[string]int)
	mscores["Chetan"] = 90
	mscores["John"] = 75
	mscores["Alice"] = 30

	// Returns Alice score: 30
	fmt.Println("Alice score:", mscores["Alice"])

	// Iterating over contents of a map, code returns
	// Key: Alice Value: 30
	// Key: Chetan Value: 90
	// Key: John Value: 75
	for key, value := range mscores {
		fmt.Println("Key:", key, "Value:", value)
	}

	// Returns Bob's score: 0 (uses the zero value)
	fmt.Println("Bob's score:", mscores["Bob"])

	// Returns Length of mscores map: 3
	fmt.Println("Length of mscores map:", len(mscores))

	// Checks if the key exists in a map
	// i returns the value for the key if exists or returns the zero value
	// ok returns bool value indicating if the key exists
	i, ok := mscores["Bob"]
	// Returns i, ok 0 false
	// As the key Bob doesnt exist, i returns zero value 0
	// and ok returns false which indicates non existence of key
	fmt.Println("i, ok", i, ok)

	// Delete element from the map
	delete(mscores, "Alice")
	// Returns mscores map[John:75 Chetan:90]
	// Alice key is removed from the map
	fmt.Println("mscores", mscores)

}