Chapter 8 — Objects

Object — real hayotdagi narsalarni ifodalash uchun ishlatiladigan, key-value juftliklaridan iborat ma'lumot tuzilmasi.

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8.1 Object nima?

Simple Explanation

Object — bir nechta xususiyat (property)ni birgalikda saqlaydigan tuzilma. Har bir property key: value shaklida yoziladi.

Why Does It Exist?

Bitta odamning ismi, yoshi va shahrini alohida-alohida variable'larda saqlash o'rniga, ularni bitta object ichida birlashtirish mumkin.

Real-Life Analogy

🪪 Object — bu shaxsning pasporti: ism, yosh, manzil kabi ma'lumotlar bitta hujjatda (object) jamlangan.

Example

script.js
JavaScriptNusxalash
01let person = {
02    name: "Ali",
03    age: 25,
04    city: "Toshkent"
05};
06 
07console.log(person.name); // "Ali"

Explanation

person — object, name, age, city — uning propertylari (xususiyatlari).

8.2 Propertylarga murojaat qilish

Simple Explanation

Object propertylariga ikki xil usulda murojaat qilish mumkin: dot notation va bracket notation.

Example

script.js
JavaScriptNusxalash
01let user = { name: "Vali", age: 30 };
02 
03console.log(user.name);      // Dot notation
04console.log(user["age"]);    // Bracket notation

Jadval

Example — Dynamic key

script.js
JavaScriptNusxalash
01let key = "age";
02console.log(user[key]); // 30

⚠️ Common Mistake
Dinamik key bilan user.key yozish ishlamaydi — bu userning "key" degan propertysini qidiradi, ageni emas. Bunday holatda albatta user[key] ishlatish kerak.

8.3 Property qo'shish, o'zgartirish, o'chirish

Example

script.js
JavaScriptNusxalash
01let car = { brand: "Toyota" };
02 
03car.model = "Camry";     // qo'shish
04car.brand = "Honda";     // o'zgartirish
05delete car.model;        // o'chirish
06 
07console.log(car); // { brand: "Honda" }

8.4 Object ichida function (Method)

Simple Explanation

Object propertysi function ham bo'lishi mumkin — bunday holatda uni method deb ataymiz.

Example

script.js
JavaScriptNusxalash
01let person = {
02    name: "Dilnoza",
03    greet: function () {
04        console.log("Salom, men " + this.name);
05    }
06};
07 
08person.greet(); // "Salom, men Dilnoza"

Explanation

this — methodni chaqirayotgan object'ga ishora qiladi. Bu haqda Chapter 13'da batafsil to'xtalamiz.

Qisqa yozish (ES6 Method Shorthand)

script.js
JavaScriptNusxalash
01let person = {
02    name: "Dilnoza",
03    greet() {
04        console.log("Salom, men " + this.name);
05    }
06};

8.5 Object.keys(), Object.values(), Object.entries()

Jadval

Example

script.js
JavaScriptNusxalash
01let book = { title: "Sariq devni minib", pages: 320 };
02 
03console.log(Object.keys(book));   // ["title", "pages"]
04console.log(Object.values(book)); // ["Sariq devni minib", 320]
05console.log(Object.entries(book)); // [["title", "..."], ["pages", 320]]

💡 Key Idea
Bu metodlar object bilan for...of loop ishlatishga imkon beradi, chunki for...indan farqli, ular array qaytaradi.

script.js
JavaScriptNusxalash
01for (let [key, value] of Object.entries(book)) {
02    console.log(key + ": " + value);
03}

8.6 Nested Objects

Simple Explanation

Object ichida object bo'lishi mumkin — bu murakkab ma'lumot tuzilmalarini ifodalash uchun ishlatiladi.

Example

script.js
JavaScriptNusxalash
01let user = {
02    name: "Aziz",
03    address: {
04        city: "Samarqand",
05        street: "Registon ko'chasi"
06    }
07};
08 
09console.log(user.address.city); // "Samarqand"

🔗 Connection
Nested object'larga xavfsiz murojaat qilish uchun Chapter 3'da o'rgangan Optional Chaining (?.) juda foydali:
console.log(user.address?.zip) — xatolik bermaydi, undefined qaytaradi.

8.7 Object.freeze()

Simple Explanation

Object'ni "muzlatib" qo'yish — uning propertylarini o'zgartirib bo'lmaydigan qilish.

Example

script.js
JavaScriptNusxalash
01const settings = Object.freeze({ theme: "dark" });
02 
03settings.theme = "light"; // e'tiborga olinmaydi
04 
05console.log(settings.theme); // "dark"

🔥 Important
const bilan e'lon qilingan object'ning o'zi qayta assign qilinmaydi, lekin ichidagi propertylarini o'zgartirish mumkin — agar Object.freeze() ishlatilmasa.

📝 Practice Exercises

🟢 Exercise 1 — Easy

Task:
name, age, profession propertylariga ega object yarating va uning barcha qiymatlarini konsolga chiqaring.
Required Concepts:

• Object literal
• Dot notation
  Hint:
  object.propertyName shaklidan foydalaning.

🟡 Exercise 2 — Medium

Task:
Berilgan object ichidagi barcha key va value juftliklarini "key: value" formatida konsolga chiqaring.

script.js
JavaScriptNusxalash
01let product = { name: "Laptop", price: 1200, inStock: true };

Required Concepts:

• Object.entries()
• for...of
  Hint:
  for (let [key, value] of Object.entries(product)) dan foydalaning.

🔴 Exercise 3 — Hard

Task:
Ikki object'ni birlashtirib, yangi object yaratadigan function yozing (agar bir xil key bo'lsa, ikkinchi object'ning qiymati ustunlik qilsin).
Required Concepts:

• Spread operator yoki Object.assign()
  Hint:
  { ...obj1, ...obj2 } sintaksisidan foydalaning (Chapter 16'da batafsil o'rganiladi).

🔮 Predict the Output

script.js
JavaScriptNusxalash
01let obj1 = { value: 10 };
02let obj2 = obj1;
03 
04obj2.value = 20;
05 
06console.log(obj1.value);

🧠 Think first! Javobni ko'rishdan oldin kamida 30 soniya o'ylang.

<details> <summary>Answer</summary> 20

Why?
Object — reference type (Array kabi). obj2 = obj1 object'ning nusxasini emas, xuddi shu object'ga havolani yaratadi. Shuning uchun obj2ni o'zgartirish obj1ga ham ta'sir qiladi.

</details>

🐛 Debugging Challenge

Quyidagi kodda muammo bor:

script.js
JavaScriptNusxalash
01let user = {
02    name: "Karim",
03    greet: function () {
04        console.log("Salom, " + name);
05    }
06};
07 
08user.greet();

Your Task:

• Kod ishga tushganda nima bo'lishini bashorat qiling.
• Nima uchun xatolik yuz berishini tushuntiring.
• Kodni tuzating.

<details> <summary>Solution</summary> Muammo: Function ichida `name` deb yozilgan, lekin bu global scope'da mavjud bo'lmagan variable. Object propertysiga murojaat qilish uchun `this.name` yozish kerak edi.

Yechim:

script.js
JavaScriptNusxalash
01let user = {
02    name: "Karim",
03    greet: function () {
04        console.log("Salom, " + this.name);
05    }
06};
07 
08user.greet(); // "Salom, Karim"

</details>

📌 Chapter Summary

• Object — key-value juftliklaridan iborat ma'lumot tuzilmasi.
• Propertylarga dot yoki bracket notation orqali murojaat qilinadi.
• Object ichidagi function — method deyiladi, u ichida this ishlatiladi.
• Object.keys/values/entries — object bilan ishlashni osonlashtiradi.
• Object — reference type.

🎯 Key Takeaways

• Dinamik key uchun bracket notation (obj[key]) ishlatiladi.
• Method ichida this — o'sha object'ga ishora qiladi.
• Object.entries() object'ni for...of bilan aylanib chiqishga imkon beradi.
• Object — reference type, = orqali nusxalash asl object'ga ham ta'sir qiladi.
• Object.freeze() object'ni to'liq o'zgarmas qilib qo'yadi.

⚡ Quick Cheat Sheet

script.js
JavaScriptNusxalash
01let obj = {
02    key: "value",
03    method() {
04        return this.key;
05    }
06};
07 
08obj.key;          // dot notation
09obj["key"];       // bracket notation
10 
11delete obj.key;   // o'chirish
12 
13Object.keys(obj);    // kalitlar
14Object.values(obj);  // qiymatlar
15Object.entries(obj); // juftliklar
16 
17Object.freeze(obj);  // o'zgarmas qilish

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