This content originally appeared on DEV Community and was authored by Islom Abdulakhatov
JavaScript brauzerda ishlayotganida, uni to’g’ridan-to’g’ri tushuna olmasligi sababli uni mashina tushunadigan tilga aylantirish kerak ya’ni o’zi tushunadigan tilga. Brauzerning JavaScript engine(mexaniz)ni JavaScript kodiga duch kelganida, u biz yozgan JavaScript kodini “translation(tarjima)” qiladi va bajarilishini boshqaradigan maxsus muhit yaratadi. Bu muhit Execution context deb ataladi.
**Execution context global scope va function scope ga ega bo’lishi mumkin. JavaScript birinchi marta ishlay boshlaganida, u global scope yaratadi.
Keyin, JavaScript parse(tahlil) qilinadi va o’zgaruvchi va funksiya deklaratsiyasini xotiraga saqlaydi.
Nihoyat, kod xotirada saqlangan o’zgaruvchilar ishga tushiriladi.
Execution context - har bir block kod uchun JavaScript tomonidan ochiladigan ma’lumotlar bloki bo’lib, ayni damda ishlayotgan kod uchun kerak bo’ladigan barcha ma’lumotlarni o’zida jamlaydi. Masalan, o’zgaruvchilar/funksiyalar/this kalit so’zi
var x = 10;
var y = 20;
Creation Phase:
- x variable is allocated memory and stores “undefined”
- y variable is allocated memory and stores “undefined”
Execution Phase:
- Places the value of 10 into the x variable
- Places the value of 20 into the y variable
This content originally appeared on DEV Community and was authored by Islom Abdulakhatov
Islom Abdulakhatov | Sciencx (2024-06-29T17:08:00+00:00) Execution Context. Retrieved from https://www.scien.cx/2024/06/29/execution-context/
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