Question

What's the output?

// counter.js
let counter = 10;
export default counter;

// index.js
import myCounter from './counter';

myCounter += 1;

console.log(myCounter);

• A: 10
• B: 11
• C: Error
• D: NaN

Answer 1

Answer: C

An imported module is read-only: you cannot modify the imported module. Only the module that exports them can change its value.

When we try to increment the value of myCounter, it throws an error: myCounter is read-only and cannot be modified.