Question

Consider the __init__ constructor method for the Python implementation of a node within a binary tree. The binary tree will aim to require minimal space by having only one tree node per search key.

How would this constructor method differ between a Set and a Map?

How might this constructor method differ between a Map and a Multi-map?

How might this constructor method differ between a Set and a Multi-Set?

Answer 1

Developers usually just use regular JavaScript objects when they want maps. Stuff is mapped in an object by using strings as a key and this is possible with any kind of Object in Javascript. var obj- obj.foo-"bar"; console.log(obj.foo); //logs "bar" In ECMAScript 6, the new type Map can be used very similar to a regular object. var map new MapO; map.set("foo", "bar") console.log(map.get("foo")); //logs "bar"

var animalSounds-new Map) animalSounds.set("dog", "woof") animalSounds.set ("cat", "meow") animalSounds.set("frog", "ribbit"); console.log(animalSounds.size); //logs 3 console.log(animalSounds.has ("dog")) //logs true animalSounds.delete("dog"); console.log(animalSounds.size); //logs 2 console.log(animalSounds.has ("dog")); //logs false animalSounds.clear; console.log(animalSounds.size); //logs

var userId, usersobj, usersMap; usersObj = { 1: "sally" 2: "bob", 3· "Jane" d: console.log(usersObj[1); //logs "sally", toString called on 1 for (userId in usersObj) console.log(userId, typeof userId);//logs 1. .3, "string" console.log("This is never logged because userId is a string."); With objects, developers have been able to use numbers as property names, or keys as it were, but when this is done the number is actually console.log(users0bj[1]); //logs "sally", toString called on 1 sally

usersMap-new Map); usersMap.set (1, "sally") usersMap.set (2, "bob"); usersMap.set (3, "jane") console.log(usersMap.get(1)) //logs "sally" usersMap.forEach(function (username, userId) console.log(userId, typeof userId); //logs 1..3, "number" if (userId -1) { console.log("We found sally." 3)5 jsfiddle (created and tested with Firefox Nightly) 1 "number" "We found sally." 2 "number" 3 "number

var map; map -new Map); map.set(true, [ 1+1 2", "cows are animals", "grass is green", map.set(false, [ "the moon is made from cheese", "the earth is flat", "pyramids were made by aliens"P map.forEach(function (value, key) console.log(typeof key, key); 3)5