javascript - Does ES6 module importing execute the code inside the imported file?

Question

Does the code inside the js file gets run during the import? if yes, then once or each time? e.g.

// a.js
console.log("A");
const a = "a"; 
export default a;

// b.js
import a from "./a"; // => console logs?

// c.js
import a from "./a"; // => console logs again?

Answer 1

Yes, it does, exactly one time.

See http://www.ecma-international.org/ecma-262/6.0/#sec-abstract-module-records:

Do nothing if this module has already been evaluated. Otherwise, transitively evaluate all module dependences of this module and then evaluate this module