🔰runtime

JS ⟩ concepts ⟩ runtime

the period when a program is running (generally after compile-time).

⭐️ 重點

scopes

• determined at compile-time.

• but created at runtime (each time a scope needs to run).

• identifiers are registered to respective scope during compile-time.

• but in sloppy mode, you can cheat it at runtime. ( 👉 modify current scope at runtime❗️❗)

this

• is not fixed in a method.

• does not necessarily refer to the object containing the method.

• is passed (at runtime) by the function call. 👉 method binding.

parameter vs. argument

• parameter(s) live in function's definition (compile-time)

• argument(s) live in call sites (runtime, may be different on each call)

🔴 主題

• dynamically typed - the type of a value can be changed at runtime.

• dynamic binding (the value of an identifier is not determined until runtime)

👥 相關

• compilation - how JS is compiled

• compare：compile-time

• runtime error

• scopes are created at runtime.

📗 參考

• Baeldung ⟩ Runtime vs. Compile Time