{"id":87073,"date":"2024-12-06T17:46:43","date_gmt":"2024-12-06T14:16:43","guid":{"rendered":"https:\/\/nabfollower.com\/blog\/a-slightly-better-map-can-get-you-there-more-easily-3h6j\/"},"modified":"2024-12-06T17:46:43","modified_gmt":"2024-12-06T14:16:43","slug":"a-slightly-better-map-can-get-you-there-more-easily-3h6j","status":"publish","type":"post","link":"https:\/\/nabfollower.com\/blog\/a-slightly-better-map-can-get-you-there-more-easily-3h6j\/","title":{"rendered":"\u06cc\u06a9 \u00ab\u0646\u0642\u0634\u0647\u00bb \u06a9\u0645\u06cc \u0628\u0647\u062a\u0631\u060c \u062e\u0648\u0627\u0646\u062f\u0646 \u06a9\u062f \u0634\u0645\u0627 \u0631\u0627 \u0622\u0633\u0627\u0646\u200c\u062a\u0631 \u0645\u06cc\u200c\u06a9\u0646\u062f…"},"content":{"rendered":"

Summarize this content to 400 words in Persian Lang
\n \u062f\u0631 \u062c\u0627\u0648\u0627 \u0627\u0633\u06a9\u0631\u06cc\u067e\u062a\u060c Map \u06cc\u06a9 \u06a9\u0644\u0627\u0633 \u062f\u0627\u062e\u0644\u06cc \u0628\u0633\u06cc\u0627\u0631 \u0645\u0641\u06cc\u062f \u0627\u0633\u062a \u06a9\u0647 \u06cc\u06a9 \u062c\u0633\u062a\u062c\u0648\u06cc O(1) \u0628\u06cc\u0646 \u06cc\u06a9 \u06a9\u0644\u06cc\u062f \u0648 \u06cc\u06a9 \u0645\u0642\u062f\u0627\u0631 \u0627\u06cc\u062c\u0627\u062f \u0645\u06cc \u06a9\u0646\u062f.<\/p>\n

const myMap = new Map()<\/p>\n

for(const file of files) {
\n const [,extension] = file.name.split(“.”)
\n if(!myMap.has(extension)) {
\n myMap.set(extension, [])
\n }
\n myMap.get(extension).push(file)
\n}<\/p>\n

\u0648\u0627\u0631\u062f \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u0634\u0648\u06cc\u062f<\/p>\n

\u0627\u0632 \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u062e\u0627\u0631\u062c \u0634\u0648\u06cc\u062f<\/p>\n

\u0645\u06cc\u200c\u062a\u0648\u0627\u0646\u06cc\u062f \u0627\u0632 Maps \u0628\u0631\u0627\u06cc \u0627\u0646\u0648\u0627\u0639 \u06a9\u0627\u0631\u0647\u0627\u06cc\u06cc \u06a9\u0647 \u0627\u062d\u062a\u0645\u0627\u0644\u0627\u064b \u0645\u0631\u062a\u0628\u0627\u064b \u0627\u0646\u062c\u0627\u0645 \u0645\u06cc\u200c\u062f\u0647\u06cc\u062f \u0627\u0633\u062a\u0641\u0627\u062f\u0647 \u06a9\u0646\u06cc\u062f:<\/p>\n

\u0627\u06cc\u062c\u0627\u062f \u0644\u06cc\u0633\u062a \u0647\u0627\u06cc \u06af\u0631\u0648\u0647 \u0628\u0646\u062f\u06cc \u0634\u062f\u0647 \u0627\u0632 \u062f\u0627\u062f\u0647 \u0647\u0627\u060c \u0645\u0627\u0646\u0646\u062f \u0645\u062b\u0627\u0644 \u0628\u0627\u0644\u0627 \u06af\u0631\u0648\u0647 \u0628\u0646\u062f\u06cc \u0628\u0631 \u0627\u0633\u0627\u0633 \u067e\u0633\u0648\u0646\u062f \u0641\u0627\u06cc\u0644
\n\u062c\u0645\u0639\u200c\u0622\u0648\u0631\u06cc \u062f\u0627\u062f\u0647\u200c\u0647\u0627\u060c \u0645\u0627\u0646\u0646\u062f \u0634\u0645\u0627\u0631\u0634 \u06cc\u0627 \u062c\u0645\u0639 \u06a9\u0631\u062f\u0646 \u0645\u0642\u0627\u062f\u06cc\u0631 \u062f\u0631 \u0637\u06cc\u0641\u06cc \u0627\u0632 \u06a9\u0644\u06cc\u062f\u0647\u0627<\/p>\n

const items = [‘apple’,’apple’,’orange’,’banana’,’apple’];
\nconst counts = new Map();
\nfor (const item of items) {
\n counts.set(item, (counts.get(item) || 0) + 1);
\n}<\/p>\n

\u0648\u0627\u0631\u062f \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u0634\u0648\u06cc\u062f<\/p>\n

\u0627\u0632 \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u062e\u0627\u0631\u062c \u0634\u0648\u06cc\u062f<\/p>\n

\u0627\u06cc\u062c\u0627\u062f \u062c\u0633\u062a\u062c\u0648\u0647\u0627\u06cc \u0633\u0631\u06cc\u0639 \u0628\u0631\u0627\u06cc \u0627\u0633\u062a\u0641\u0627\u062f\u0647 \u062f\u0631 \u0645\u0631\u0627\u062d\u0644 \u0628\u0639\u062f\u06cc<\/p>\n

const users = [
\n {id:1,name:’A’,role:’admin’},
\n {id:2,name:’B’,role:’user’},
\n {id:3,name:’C’,role:’user’}
\n];
\nconst userMap = new Map();
\nfor (const u of users) {
\n userMap.set(u.id, u);
\n}<\/p>\n

\u0648\u0627\u0631\u062f \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u0634\u0648\u06cc\u062f<\/p>\n

\u0627\u0632 \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u062e\u0627\u0631\u062c \u0634\u0648\u06cc\u062f<\/p>\n

\u0646\u0642\u0634\u0647 \u0628\u0647 \u0627\u0633\u062a\u0641\u0627\u062f\u0647 \u0627\u0632 \u06cc\u06a9 \u0634\u06cc \u0633\u0627\u062f\u0647 \u062a\u0631\u062c\u06cc\u062d \u062f\u0627\u062f\u0647 \u0645\u06cc \u0634\u0648\u062f ({}) \u0628\u0647 \u0686\u0646\u062f \u062f\u0644\u06cc\u0644\u060c \u062a\u0627 \u0632\u0645\u0627\u0646\u06cc \u06a9\u0647 \u0645\u062c\u0628\u0648\u0631 \u0646\u0628\u0627\u0634\u06cc\u062f \u0646\u062a\u06cc\u062c\u0647 \u0631\u0627 \u0628\u0627 \u0627\u0633\u062a\u0641\u0627\u062f\u0647 \u0627\u0632 a \u0630\u062e\u06cc\u0631\u0647 \u06a9\u0646\u06cc\u062f stringify:<\/p>\n

\u0645\u06cc \u062a\u0648\u0627\u0646\u062f \u06a9\u0644\u06cc\u062f\u0647\u0627\u06cc\u06cc \u0631\u0627 \u0628\u06af\u06cc\u0631\u062f \u06a9\u0647 \u0631\u0634\u062a\u0647 \u0627\u06cc \u0646\u06cc\u0633\u062a\u0646\u062f
\n\u062d\u062a\u06cc \u0627\u06af\u0631 \u0627\u0632 \u06a9\u0644\u06cc\u062f\u0647\u0627\u06cc \u0631\u0634\u062a\u0647 \u0627\u06cc \u0627\u0633\u062a\u0641\u0627\u062f\u0647 \u0645\u06cc \u06a9\u0646\u06cc\u062f\u060c \u06a9\u0645\u06cc \u0633\u0631\u06cc\u0639\u062a\u0631 \u0627\u0632 \u06cc\u06a9 \u0634\u06cc\u0621 \u0627\u0633\u062a<\/p>\n

\u0645\u0645\u06a9\u0646 \u0627\u0633\u062a \u0646\u06af\u0631\u0627\u0646\u06cc\u200c\u0647\u0627\u06cc \u0632\u06cc\u0627\u062f\u06cc \u0648\u062c\u0648\u062f \u062f\u0627\u0634\u062a\u0647 \u0628\u0627\u0634\u062f\u060c \u0627\u0645\u0627 \u0627\u06af\u0631 \u0634\u06cc\u0626\u06cc \u06a9\u0647 \u062f\u0631 \u0646\u0642\u0634\u0647 \u0630\u062e\u06cc\u0631\u0647 \u0645\u06cc\u200c\u06a9\u0646\u06cc\u062f \u0646\u06cc\u0627\u0632 \u0628\u0647 \u0633\u0627\u062e\u062a \u062f\u0627\u0631\u062f\u060c \u06a9\u0647 \u0627\u0632 \u06cc\u06a9 \u0622\u0631\u0627\u06cc\u0647 \u0633\u0627\u062f\u0647 \u06af\u0631\u0641\u062a\u0647 \u062a\u0627 \u06cc\u06a9 \u0634\u06cc \u067e\u06cc\u0686\u06cc\u062f\u0647 \u0627\u0633\u062a\u060c \u0627\u06cc\u0646 \u0628\u0627\u06cc\u062f \u0628\u0627 \u06a9\u062f\u06cc \u06a9\u0647 \u0627\u0632 \u0622\u0646 \u0627\u0633\u062a\u0641\u0627\u062f\u0647 \u0645\u06cc\u200c\u06a9\u0646\u062f\u060c \u0622\u0645\u06cc\u062e\u062a\u0647 \u0634\u0648\u062f.<\/p>\n

const map = new Map()<\/p>\n

for(const item of items) {
\n if(!map.has(item.type)) {
\n const newType = new Type(item.type, getInfoForType(item.type))
\n map.set(item.type, newType)
\n }
\n map.get(item.type).doSomething(item)<\/p>\n

}<\/p>\n

\u0648\u0627\u0631\u062f \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u0634\u0648\u06cc\u062f<\/p>\n

\u0627\u0632 \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u062e\u0627\u0631\u062c \u0634\u0648\u06cc\u062f<\/p>\n

\u0627\u06cc\u0646 “\u0645\u06cc \u062a\u0648\u0627\u0646\u062f” \u062e\u0648\u0628 \u0627\u0633\u062a\u060c \u0627\u0645\u0627 \u0627\u06af\u0631 \u0646\u06cc\u0627\u0632 \u0628\u0647 \u0628\u0647 \u0631\u0648\u0632 \u0631\u0633\u0627\u0646\u06cc \u06cc\u0627 \u0645\u0642\u062f\u0627\u0631\u062f\u0647\u06cc \u0627\u0648\u0644\u06cc\u0647 \u062f\u0631 \u0686\u0646\u062f\u06cc\u0646 \u0645\u06a9\u0627\u0646 \u062f\u0627\u0634\u062a\u0647 \u0628\u0627\u0634\u06cc\u062f\u060c \u0646\u06af\u0647 \u062f\u0627\u0634\u062a\u0646 DRY \u062f\u0634\u0648\u0627\u0631\u062a\u0631 \u0645\u06cc \u0634\u0648\u062f.<\/p>\n

\u0628\u0647 \u0647\u0645\u06cc\u0646 \u062f\u0644\u06cc\u0644 \u0645\u0646 \u0627\u0632 \u06cc\u06a9 \u06a9\u0644\u0627\u0633 MapPlus \u0627\u0633\u062a\u0641\u0627\u062f\u0647 \u0645\u06cc \u06a9\u0646\u0645\u060c \u06a9\u0647 \u067e\u0633\u0648\u0646\u062f\u06cc \u0628\u0631\u0627\u06cc Map \u0627\u0633\u062a \u06a9\u0647 \u06cc\u06a9 \u062a\u0627\u0628\u0639 \u0627\u0648\u0644\u06cc\u0647 \u06a9\u0644\u06cc\u062f \u06af\u0645 \u0634\u062f\u0647 \u0631\u0627 \u0627\u0631\u0627\u0626\u0647 \u0645\u06cc \u062f\u0647\u062f \u06a9\u0647 \u0645\u06cc \u062a\u0648\u0627\u0646\u062f \u0628\u0647 \u0633\u0627\u0632\u0646\u062f\u0647 \u06cc\u0627 \u0628\u0647 \u0639\u0646\u0648\u0627\u0646 \u067e\u0627\u0631\u0627\u0645\u062a\u0631 \u062f\u0648\u0645 \u0628\u0631\u0627\u06cc get \u0627\u06af\u0631 \u0645\u0642\u062f\u0627\u0631\u062f\u0647\u06cc \u0627\u0648\u0644\u06cc\u0647 \u0628\u0647 \u0627\u0637\u0644\u0627\u0639\u0627\u062a \u0632\u0645\u06cc\u0646\u0647 \u0641\u0631\u0627\u062a\u0631 \u0627\u0632 \u06a9\u0644\u06cc\u062f \u0646\u06cc\u0627\u0632 \u062f\u0627\u0634\u062a\u0647 \u0628\u0627\u0634\u062f.<\/p>\n

class MapPlus extends Map {
\n constructor(missingFunction) {
\n super()
\n this.missingFunction = missingFunction
\n }<\/p>\n

get(key, createIfMissing = this.missingFunction) {
\n let result = super.get(key)
\n if (!result && createIfMissing) {
\n result = createIfMissing(key)
\n if (result && result.then) {
\n const promise = result.then((value) => {
\n super.set(key, value)
\n return value
\n })
\n super.set(key, promise)
\n } else {
\n super.set(key, result)
\n }
\n }
\n return result
\n }
\n}<\/p>\n

\u0648\u0627\u0631\u062f \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u0634\u0648\u06cc\u062f<\/p>\n

\u0627\u0632 \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u062e\u0627\u0631\u062c \u0634\u0648\u06cc\u062f<\/p>\n

\u0628\u0627 \u0627\u06cc\u0646 \u06a9\u0627\u0631 \u0641\u0642\u0637 \u0645\u06cc \u062a\u0648\u0627\u0646\u06cc\u062f \u06a9\u0627\u0631\u0647\u0627\u06cc\u06cc \u0645\u0627\u0646\u0646\u062f:<\/p>\n

const map = new MapPlus(()=>[])<\/p>\n

for(const item of items) {
\n map.get(item.type).push(item)
\n}<\/p>\n

\u0648\u0627\u0631\u062f \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u0634\u0648\u06cc\u062f<\/p>\n

\u0627\u0632 \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u062e\u0627\u0631\u062c \u0634\u0648\u06cc\u062f<\/p>\n

\u0627\u06af\u0631 \u06a9\u0644\u06cc\u062f \u0627\u0632 \u062f\u0633\u062a \u0631\u0641\u062a\u0647 \u0628\u0627\u0634\u062f\u060c \u0641\u0642\u0637 \u06cc\u06a9 \u0622\u0631\u0627\u06cc\u0647 \u062e\u0627\u0644\u06cc \u0627\u06cc\u062c\u0627\u062f \u0645\u06cc \u06a9\u0646\u062f\u060c \u0627\u0645\u0627 \u062e\u0648\u062f \u062d\u0644\u0642\u0647 \u0633\u0627\u062f\u0647 \u0648 \u062a\u0645\u06cc\u0632 \u0646\u06af\u0647 \u062f\u0627\u0634\u062a\u0647 \u0645\u06cc \u0634\u0648\u062f \u0648 \u0641\u0642\u0637 \u0628\u0647 \u0627\u06cc\u062c\u0627\u062f \u0644\u06cc\u0633\u062a \u0645\u0631\u0628\u0648\u0637 \u0645\u06cc \u0634\u0648\u062f.<\/p>\n

\u0645\u0646 \u0627\u063a\u0644\u0628 \u0628\u0647 \u062f\u0648 \u0633\u0637\u062d \u0627\u0632 \u0627\u06cc\u0646 \u0646\u06cc\u0627\u0632 \u062f\u0627\u0631\u0645\u060c \u0628\u0646\u0627\u0628\u0631\u0627\u06cc\u0646 \u0646\u0642\u0634\u0647 \u0647\u0627 \u0631\u0627 \u0628\u0647 \u0627\u06cc\u0646 \u0635\u0648\u0631\u062a \u062a\u0639\u0631\u06cc\u0641 \u0645\u06cc \u06a9\u0646\u0645:<\/p>\n

const map = new MapPlus(()=>new MapPlus(()=>[]))
\nfor(const item of items) {
\n map.get(item.type).get(item.subType).push(item)
\n}<\/p>\n

\u0648\u0627\u0631\u062f \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u0634\u0648\u06cc\u062f<\/p>\n

\u0627\u0632 \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u062e\u0627\u0631\u062c \u0634\u0648\u06cc\u062f<\/p>\n

\u062a\u0627\u0628\u0639 \u0633\u0627\u0632\u0646\u062f\u0647 \u0645\u06cc \u0634\u0648\u062f key \u0627\u0633\u062a\u0641\u0627\u062f\u0647 \u0645\u06cc \u0634\u0648\u062f \u0628\u0646\u0627\u0628\u0631\u0627\u06cc\u0646 \u0645\u0627 \u0647\u0645\u0686\u0646\u06cc\u0646 \u0645\u06cc \u062a\u0648\u0627\u0646\u06cc\u0645 \u0627\u0646\u062c\u0627\u0645 \u062f\u0647\u06cc\u0645:<\/p>\n

const map = new MapPlus((type)=>new Type(type, getInfoForType(type))<\/p>\n

for(const item of items) {
\n map.get(item.type).doSomething(item)
\n}<\/p>\n

\u0648\u0627\u0631\u062f \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u0634\u0648\u06cc\u062f<\/p>\n

\u0627\u0632 \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u062e\u0627\u0631\u062c \u0634\u0648\u06cc\u062f<\/p>\n

\n

\u062f\u0631 \u062c\u0627\u0648\u0627 \u0627\u0633\u06a9\u0631\u06cc\u067e\u062a\u060c Map<\/code> \u06cc\u06a9 \u06a9\u0644\u0627\u0633 \u062f\u0627\u062e\u0644\u06cc \u0628\u0633\u06cc\u0627\u0631 \u0645\u0641\u06cc\u062f \u0627\u0633\u062a \u06a9\u0647 \u06cc\u06a9 \u062c\u0633\u062a\u062c\u0648\u06cc O(1) \u0628\u06cc\u0646 \u06cc\u06a9 \u06a9\u0644\u06cc\u062f \u0648 \u06cc\u06a9 \u0645\u0642\u062f\u0627\u0631 \u0627\u06cc\u062c\u0627\u062f \u0645\u06cc \u06a9\u0646\u062f.<\/p>\n

\n
const<\/span> myMap<\/span> =<\/span> new<\/span> Map<\/span>()<\/span>\n\nfor<\/span>(<\/span>const<\/span> file<\/span> of<\/span> files<\/span>)<\/span> {<\/span>\n    const<\/span> [,<\/span>extension<\/span>]<\/span> =<\/span> file<\/span>.<\/span>name<\/span>.<\/span>split<\/span>(<\/span>\"<\/span>.<\/span>\"<\/span>)<\/span>\n    if<\/span>(<\/span>!<\/span>myMap<\/span>.<\/span>has<\/span>(<\/span>extension<\/span>))<\/span> {<\/span>\n        myMap<\/span>.<\/span>set<\/span>(<\/span>extension<\/span>,<\/span> [])<\/span>\n    }<\/span>\n    myMap<\/span>.<\/span>get<\/span>(<\/span>extension<\/span>).<\/span>push<\/span>(<\/span>file<\/span>)<\/span>\n}<\/span>\n\n<\/code><\/pre>\n
\n
\n    \u0648\u0627\u0631\u062f \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u0634\u0648\u06cc\u062f<\/title>\n    \n<\/svg><\/p>\n
    \u0627\u0632 \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u062e\u0627\u0631\u062c \u0634\u0648\u06cc\u062f<\/title>\n    \n<\/svg><\/p>\n<\/div>\n<\/div>\n<\/div>\n
\u0645\u06cc\u200c\u062a\u0648\u0627\u0646\u06cc\u062f \u0627\u0632 Maps \u0628\u0631\u0627\u06cc \u0627\u0646\u0648\u0627\u0639 \u06a9\u0627\u0631\u0647\u0627\u06cc\u06cc \u06a9\u0647 \u0627\u062d\u062a\u0645\u0627\u0644\u0627\u064b \u0645\u0631\u062a\u0628\u0627\u064b \u0627\u0646\u062c\u0627\u0645 \u0645\u06cc\u200c\u062f\u0647\u06cc\u062f \u0627\u0633\u062a\u0641\u0627\u062f\u0647 \u06a9\u0646\u06cc\u062f:<\/p>\n
    \n
  • \n
    \u0627\u06cc\u062c\u0627\u062f \u0644\u06cc\u0633\u062a \u0647\u0627\u06cc \u06af\u0631\u0648\u0647 \u0628\u0646\u062f\u06cc \u0634\u062f\u0647 \u0627\u0632 \u062f\u0627\u062f\u0647 \u0647\u0627\u060c \u0645\u0627\u0646\u0646\u062f \u0645\u062b\u0627\u0644 \u0628\u0627\u0644\u0627 \u06af\u0631\u0648\u0647 \u0628\u0646\u062f\u06cc \u0628\u0631 \u0627\u0633\u0627\u0633 \u067e\u0633\u0648\u0646\u062f \u0641\u0627\u06cc\u0644<\/p>\n<\/li>\n
  • \n
    \u062c\u0645\u0639\u200c\u0622\u0648\u0631\u06cc \u062f\u0627\u062f\u0647\u200c\u0647\u0627\u060c \u0645\u0627\u0646\u0646\u062f \u0634\u0645\u0627\u0631\u0634 \u06cc\u0627 \u062c\u0645\u0639 \u06a9\u0631\u062f\u0646 \u0645\u0642\u0627\u062f\u06cc\u0631 \u062f\u0631 \u0637\u06cc\u0641\u06cc \u0627\u0632 \u06a9\u0644\u06cc\u062f\u0647\u0627<\/p>\n<\/li>\n<\/ul>\n
    \n
    const<\/span> items<\/span> =<\/span> [<\/span>'<\/span>apple<\/span>'<\/span>,<\/span>'<\/span>apple<\/span>'<\/span>,<\/span>'<\/span>orange<\/span>'<\/span>,<\/span>'<\/span>banana<\/span>'<\/span>,<\/span>'<\/span>apple<\/span>'<\/span>];<\/span>\nconst<\/span> counts<\/span> =<\/span> new<\/span> Map<\/span>();<\/span>\nfor <\/span>(<\/span>const<\/span> item<\/span> of<\/span> items<\/span>)<\/span> {<\/span>\n  counts<\/span>.<\/span>set<\/span>(<\/span>item<\/span>,<\/span> (<\/span>counts<\/span>.<\/span>get<\/span>(<\/span>item<\/span>)<\/span> ||<\/span> 0<\/span>)<\/span> +<\/span> 1<\/span>);<\/span>\n}<\/span>\n<\/code><\/pre>\n
    \n
    \n    \u0648\u0627\u0631\u062f \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u0634\u0648\u06cc\u062f<\/title>\n    \n<\/svg><\/p>\n
        \u0627\u0632 \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u062e\u0627\u0631\u062c \u0634\u0648\u06cc\u062f<\/title>\n    \n<\/svg><\/p>\n<\/div>\n<\/div>\n<\/div>\n
      \n
    • \u0627\u06cc\u062c\u0627\u062f \u062c\u0633\u062a\u062c\u0648\u0647\u0627\u06cc \u0633\u0631\u06cc\u0639 \u0628\u0631\u0627\u06cc \u0627\u0633\u062a\u0641\u0627\u062f\u0647 \u062f\u0631 \u0645\u0631\u0627\u062d\u0644 \u0628\u0639\u062f\u06cc\n<\/li>\n<\/ul>\n
      \n
      const<\/span> users<\/span> =<\/span> [<\/span>\n  {<\/span>id<\/span>:<\/span>1<\/span>,<\/span>name<\/span>:<\/span>'<\/span>A<\/span>'<\/span>,<\/span>role<\/span>:<\/span>'<\/span>admin<\/span>'<\/span>},<\/span>\n  {<\/span>id<\/span>:<\/span>2<\/span>,<\/span>name<\/span>:<\/span>'<\/span>B<\/span>'<\/span>,<\/span>role<\/span>:<\/span>'<\/span>user<\/span>'<\/span>},<\/span>\n  {<\/span>id<\/span>:<\/span>3<\/span>,<\/span>name<\/span>:<\/span>'<\/span>C<\/span>'<\/span>,<\/span>role<\/span>:<\/span>'<\/span>user<\/span>'<\/span>}<\/span>\n];<\/span>\nconst<\/span> userMap<\/span> =<\/span> new<\/span> Map<\/span>();<\/span>\nfor <\/span>(<\/span>const<\/span> u<\/span> of<\/span> users<\/span>)<\/span> {<\/span>\n  userMap<\/span>.<\/span>set<\/span>(<\/span>u<\/span>.<\/span>id<\/span>,<\/span> u<\/span>);<\/span>\n}<\/span>\n<\/code><\/pre>\n
      \n
      \n    \u0648\u0627\u0631\u062f \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u0634\u0648\u06cc\u062f<\/title>\n    \n<\/svg><\/p>\n
          \u0627\u0632 \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u062e\u0627\u0631\u062c \u0634\u0648\u06cc\u062f<\/title>\n    \n<\/svg><\/p>\n<\/div>\n<\/div>\n<\/div>\n
      \u0646\u0642\u0634\u0647 \u0628\u0647 \u0627\u0633\u062a\u0641\u0627\u062f\u0647 \u0627\u0632 \u06cc\u06a9 \u0634\u06cc \u0633\u0627\u062f\u0647 \u062a\u0631\u062c\u06cc\u062d \u062f\u0627\u062f\u0647 \u0645\u06cc \u0634\u0648\u062f ({}<\/code>) \u0628\u0647 \u0686\u0646\u062f \u062f\u0644\u06cc\u0644\u060c \u062a\u0627 \u0632\u0645\u0627\u0646\u06cc \u06a9\u0647 \u0645\u062c\u0628\u0648\u0631 \u0646\u0628\u0627\u0634\u06cc\u062f \u0646\u062a\u06cc\u062c\u0647 \u0631\u0627 \u0628\u0627 \u0627\u0633\u062a\u0641\u0627\u062f\u0647 \u0627\u0632 a \u0630\u062e\u06cc\u0631\u0647 \u06a9\u0646\u06cc\u062f stringify<\/code>:<\/p>\n
        \n
      • \u0645\u06cc \u062a\u0648\u0627\u0646\u062f \u06a9\u0644\u06cc\u062f\u0647\u0627\u06cc\u06cc \u0631\u0627 \u0628\u06af\u06cc\u0631\u062f \u06a9\u0647 \u0631\u0634\u062a\u0647 \u0627\u06cc \u0646\u06cc\u0633\u062a\u0646\u062f<\/li>\n
      • \u062d\u062a\u06cc \u0627\u06af\u0631 \u0627\u0632 \u06a9\u0644\u06cc\u062f\u0647\u0627\u06cc \u0631\u0634\u062a\u0647 \u0627\u06cc \u0627\u0633\u062a\u0641\u0627\u062f\u0647 \u0645\u06cc \u06a9\u0646\u06cc\u062f\u060c \u06a9\u0645\u06cc \u0633\u0631\u06cc\u0639\u062a\u0631 \u0627\u0632 \u06cc\u06a9 \u0634\u06cc\u0621 \u0627\u0633\u062a<\/li>\n<\/ul>\n
        \u0645\u0645\u06a9\u0646 \u0627\u0633\u062a \u0646\u06af\u0631\u0627\u0646\u06cc\u200c\u0647\u0627\u06cc \u0632\u06cc\u0627\u062f\u06cc \u0648\u062c\u0648\u062f \u062f\u0627\u0634\u062a\u0647 \u0628\u0627\u0634\u062f\u060c \u0627\u0645\u0627 \u0627\u06af\u0631 \u0634\u06cc\u0626\u06cc \u06a9\u0647 \u062f\u0631 \u0646\u0642\u0634\u0647 \u0630\u062e\u06cc\u0631\u0647 \u0645\u06cc\u200c\u06a9\u0646\u06cc\u062f \u0646\u06cc\u0627\u0632 \u0628\u0647 \u0633\u0627\u062e\u062a \u062f\u0627\u0631\u062f\u060c \u06a9\u0647 \u0627\u0632 \u06cc\u06a9 \u0622\u0631\u0627\u06cc\u0647 \u0633\u0627\u062f\u0647 \u06af\u0631\u0641\u062a\u0647 \u062a\u0627 \u06cc\u06a9 \u0634\u06cc \u067e\u06cc\u0686\u06cc\u062f\u0647 \u0627\u0633\u062a\u060c \u0627\u06cc\u0646 \u0628\u0627\u06cc\u062f \u0628\u0627 \u06a9\u062f\u06cc \u06a9\u0647 \u0627\u0632 \u0622\u0646 \u0627\u0633\u062a\u0641\u0627\u062f\u0647 \u0645\u06cc\u200c\u06a9\u0646\u062f\u060c \u0622\u0645\u06cc\u062e\u062a\u0647 \u0634\u0648\u062f.<\/p>\n
        \n
        \nconst<\/span> map<\/span> =<\/span> new<\/span> Map<\/span>()<\/span>\n\nfor<\/span>(<\/span>const<\/span> item<\/span> of<\/span> items<\/span>)<\/span> {<\/span>\n   if<\/span>(<\/span>!<\/span>map<\/span>.<\/span>has<\/span>(<\/span>item<\/span>.<\/span>type<\/span>))<\/span> {<\/span>\n       const<\/span> newType<\/span> =<\/span> new<\/span> Type<\/span>(<\/span>item<\/span>.<\/span>type<\/span>,<\/span> getInfoForType<\/span>(<\/span>item<\/span>.<\/span>type<\/span>))<\/span>\n       map<\/span>.<\/span>set<\/span>(<\/span>item<\/span>.<\/span>type<\/span>,<\/span> newType<\/span>)<\/span>\n   }<\/span>\n   map<\/span>.<\/span>get<\/span>(<\/span>item<\/span>.<\/span>type<\/span>).<\/span>doSomething<\/span>(<\/span>item<\/span>)<\/span>\n\n}<\/span>\n\n<\/code><\/pre>\n
        \n
        \n    \u0648\u0627\u0631\u062f \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u0634\u0648\u06cc\u062f<\/title>\n    \n<\/svg><\/p>\n
            \u0627\u0632 \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u062e\u0627\u0631\u062c \u0634\u0648\u06cc\u062f<\/title>\n    \n<\/svg><\/p>\n<\/div>\n<\/div>\n<\/div>\n
        \u0627\u06cc\u0646 “\u0645\u06cc \u062a\u0648\u0627\u0646\u062f” \u062e\u0648\u0628 \u0627\u0633\u062a\u060c \u0627\u0645\u0627 \u0627\u06af\u0631 \u0646\u06cc\u0627\u0632 \u0628\u0647 \u0628\u0647 \u0631\u0648\u0632 \u0631\u0633\u0627\u0646\u06cc \u06cc\u0627 \u0645\u0642\u062f\u0627\u0631\u062f\u0647\u06cc \u0627\u0648\u0644\u06cc\u0647 \u062f\u0631 \u0686\u0646\u062f\u06cc\u0646 \u0645\u06a9\u0627\u0646 \u062f\u0627\u0634\u062a\u0647 \u0628\u0627\u0634\u06cc\u062f\u060c \u0646\u06af\u0647 \u062f\u0627\u0634\u062a\u0646 DRY \u062f\u0634\u0648\u0627\u0631\u062a\u0631 \u0645\u06cc \u0634\u0648\u062f.<\/p>\n
        \u0628\u0647 \u0647\u0645\u06cc\u0646 \u062f\u0644\u06cc\u0644 \u0645\u0646 \u0627\u0632 \u06cc\u06a9 \u06a9\u0644\u0627\u0633 MapPlus \u0627\u0633\u062a\u0641\u0627\u062f\u0647 \u0645\u06cc \u06a9\u0646\u0645\u060c \u06a9\u0647 \u067e\u0633\u0648\u0646\u062f\u06cc \u0628\u0631\u0627\u06cc Map \u0627\u0633\u062a \u06a9\u0647 \u06cc\u06a9 \u062a\u0627\u0628\u0639 \u0627\u0648\u0644\u06cc\u0647 \u06a9\u0644\u06cc\u062f \u06af\u0645 \u0634\u062f\u0647 \u0631\u0627 \u0627\u0631\u0627\u0626\u0647 \u0645\u06cc \u062f\u0647\u062f \u06a9\u0647 \u0645\u06cc \u062a\u0648\u0627\u0646\u062f \u0628\u0647 \u0633\u0627\u0632\u0646\u062f\u0647 \u06cc\u0627 \u0628\u0647 \u0639\u0646\u0648\u0627\u0646 \u067e\u0627\u0631\u0627\u0645\u062a\u0631 \u062f\u0648\u0645 \u0628\u0631\u0627\u06cc get<\/code> \u0627\u06af\u0631 \u0645\u0642\u062f\u0627\u0631\u062f\u0647\u06cc \u0627\u0648\u0644\u06cc\u0647 \u0628\u0647 \u0627\u0637\u0644\u0627\u0639\u0627\u062a \u0632\u0645\u06cc\u0646\u0647 \u0641\u0631\u0627\u062a\u0631 \u0627\u0632 \u06a9\u0644\u06cc\u062f \u0646\u06cc\u0627\u0632 \u062f\u0627\u0634\u062a\u0647 \u0628\u0627\u0634\u062f.<\/p>\n
        \n
        class<\/span> MapPlus<\/span> extends<\/span> Map<\/span> {<\/span>\n    constructor<\/span>(<\/span>missingFunction<\/span>)<\/span> {<\/span>\n        super<\/span>()<\/span>\n        this<\/span>.<\/span>missingFunction<\/span> =<\/span> missingFunction<\/span>\n    }<\/span>\n\n    get<\/span>(<\/span>key<\/span>,<\/span> createIfMissing<\/span> =<\/span> this<\/span>.<\/span>missingFunction<\/span>)<\/span> {<\/span>\n        let<\/span> result<\/span> =<\/span> super<\/span>.<\/span>get<\/span>(<\/span>key<\/span>)<\/span>\n        if <\/span>(<\/span>!<\/span>result<\/span> &&<\/span> createIfMissing<\/span>)<\/span> {<\/span>\n            result<\/span> =<\/span> createIfMissing<\/span>(<\/span>key<\/span>)<\/span>\n            if <\/span>(<\/span>result<\/span> &&<\/span> result<\/span>.<\/span>then<\/span>)<\/span> {<\/span>\n                const<\/span> promise<\/span> =<\/span> result<\/span>.<\/span>then<\/span>((<\/span>value<\/span>)<\/span> =><\/span> {<\/span>\n                    super<\/span>.<\/span>set<\/span>(<\/span>key<\/span>,<\/span> value<\/span>)<\/span>\n                    return<\/span> value<\/span>\n                })<\/span>\n                super<\/span>.<\/span>set<\/span>(<\/span>key<\/span>,<\/span> promise<\/span>)<\/span>\n            }<\/span> else<\/span> {<\/span>\n                super<\/span>.<\/span>set<\/span>(<\/span>key<\/span>,<\/span> result<\/span>)<\/span>\n            }<\/span>\n        }<\/span>\n        return<\/span> result<\/span>\n    }<\/span>\n}<\/span>\n<\/code><\/pre>\n
        \n
        \n    \u0648\u0627\u0631\u062f \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u0634\u0648\u06cc\u062f<\/title>\n    \n<\/svg><\/p>\n
            \u0627\u0632 \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u062e\u0627\u0631\u062c \u0634\u0648\u06cc\u062f<\/title>\n    \n<\/svg><\/p>\n<\/div>\n<\/div>\n<\/div>\n
        \u0628\u0627 \u0627\u06cc\u0646 \u06a9\u0627\u0631 \u0641\u0642\u0637 \u0645\u06cc \u062a\u0648\u0627\u0646\u06cc\u062f \u06a9\u0627\u0631\u0647\u0627\u06cc\u06cc \u0645\u0627\u0646\u0646\u062f:<\/p>\n
        \n
        const<\/span> map<\/span> =<\/span> new<\/span> MapPlus<\/span>(()<\/span>=><\/span>[])<\/span>\n\nfor<\/span>(<\/span>const<\/span> item<\/span> of<\/span> items<\/span>)<\/span> {<\/span>\n    map<\/span>.<\/span>get<\/span>(<\/span>item<\/span>.<\/span>type<\/span>).<\/span>push<\/span>(<\/span>item<\/span>)<\/span>\n}<\/span>\n\n<\/code><\/pre>\n
        \n
        \n    \u0648\u0627\u0631\u062f \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u0634\u0648\u06cc\u062f<\/title>\n    \n<\/svg><\/p>\n
            \u0627\u0632 \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u062e\u0627\u0631\u062c \u0634\u0648\u06cc\u062f<\/title>\n    \n<\/svg><\/p>\n<\/div>\n<\/div>\n<\/div>\n
        \u0627\u06af\u0631 \u06a9\u0644\u06cc\u062f \u0627\u0632 \u062f\u0633\u062a \u0631\u0641\u062a\u0647 \u0628\u0627\u0634\u062f\u060c \u0641\u0642\u0637 \u06cc\u06a9 \u0622\u0631\u0627\u06cc\u0647 \u062e\u0627\u0644\u06cc \u0627\u06cc\u062c\u0627\u062f \u0645\u06cc \u06a9\u0646\u062f\u060c \u0627\u0645\u0627 \u062e\u0648\u062f \u062d\u0644\u0642\u0647 \u0633\u0627\u062f\u0647 \u0648 \u062a\u0645\u06cc\u0632 \u0646\u06af\u0647 \u062f\u0627\u0634\u062a\u0647 \u0645\u06cc \u0634\u0648\u062f \u0648 \u0641\u0642\u0637 \u0628\u0647 \u0627\u06cc\u062c\u0627\u062f \u0644\u06cc\u0633\u062a \u0645\u0631\u0628\u0648\u0637 \u0645\u06cc \u0634\u0648\u062f.<\/p>\n
        \u0645\u0646 \u0627\u063a\u0644\u0628 \u0628\u0647 \u062f\u0648 \u0633\u0637\u062d \u0627\u0632 \u0627\u06cc\u0646 \u0646\u06cc\u0627\u0632 \u062f\u0627\u0631\u0645\u060c \u0628\u0646\u0627\u0628\u0631\u0627\u06cc\u0646 \u0646\u0642\u0634\u0647 \u0647\u0627 \u0631\u0627 \u0628\u0647 \u0627\u06cc\u0646 \u0635\u0648\u0631\u062a \u062a\u0639\u0631\u06cc\u0641 \u0645\u06cc \u06a9\u0646\u0645:<\/p>\n
        \n
        const<\/span> map<\/span> =<\/span> new<\/span> MapPlus<\/span>(()<\/span>=><\/span>new<\/span> MapPlus<\/span>(()<\/span>=><\/span>[]))<\/span>\nfor<\/span>(<\/span>const<\/span> item<\/span> of<\/span> items<\/span>)<\/span> {<\/span>\n   map<\/span>.<\/span>get<\/span>(<\/span>item<\/span>.<\/span>type<\/span>).<\/span>get<\/span>(<\/span>item<\/span>.<\/span>subType<\/span>).<\/span>push<\/span>(<\/span>item<\/span>)<\/span>\n}<\/span>\n<\/code><\/pre>\n
        \n
        \n    \u0648\u0627\u0631\u062f \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u0634\u0648\u06cc\u062f<\/title>\n    \n<\/svg><\/p>\n
            \u0627\u0632 \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u062e\u0627\u0631\u062c \u0634\u0648\u06cc\u062f<\/title>\n    \n<\/svg><\/p>\n<\/div>\n<\/div>\n<\/div>\n
        \u062a\u0627\u0628\u0639 \u0633\u0627\u0632\u0646\u062f\u0647 \u0645\u06cc \u0634\u0648\u062f key<\/code> \u0627\u0633\u062a\u0641\u0627\u062f\u0647 \u0645\u06cc \u0634\u0648\u062f \u0628\u0646\u0627\u0628\u0631\u0627\u06cc\u0646 \u0645\u0627 \u0647\u0645\u0686\u0646\u06cc\u0646 \u0645\u06cc \u062a\u0648\u0627\u0646\u06cc\u0645 \u0627\u0646\u062c\u0627\u0645 \u062f\u0647\u06cc\u0645:<\/p>\n
        \n
        const<\/span> map<\/span> =<\/span> new<\/span> MapPlus<\/span>((<\/span>type<\/span>)<\/span>=><\/span>new<\/span> Type<\/span>(<\/span>type<\/span>,<\/span> getInfoForType<\/span>(<\/span>type<\/span>))<\/span>\n\nfor<\/span>(<\/span>const<\/span> item<\/span> of<\/span> items<\/span>)<\/span> {<\/span>\n    map<\/span>.<\/span>get<\/span>(<\/span>item<\/span>.<\/span>type<\/span>).<\/span>doSomething<\/span>(<\/span>item<\/span>)<\/span>\n}<\/span>\n<\/code><\/pre>\n
        \n
        \n    \u0648\u0627\u0631\u062f \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u0634\u0648\u06cc\u062f<\/title>\n    \n<\/svg><\/p>\n
            \u0627\u0632 \u062d\u0627\u0644\u062a \u062a\u0645\u0627\u0645 \u0635\u0641\u062d\u0647 \u062e\u0627\u0631\u062c \u0634\u0648\u06cc\u062f<\/title>\n    \n<\/svg><\/p>\n<\/div>\n<\/div>\n<\/div>\n