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javascript-export

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Export * from …

This syntax is used to re-export all named exports from another module. It does not work for default exports.

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// math.mjs
const add = (a, b) => a + b;
const subtract = (a, b) => a - b;
const multiply = (a, b) => a * b;

export { add, subtract };
export default multiply; // default export

File index.mj re-exports all named exports from math.mjs, in this case, add and subtract, but not multiply, since it is a default export.

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// index.mjs
export * from './math.mjs';

Now you can import all named exports from index.mjs using the following syntax:

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// main.mjs
import * as mathfunc from './index.mjs';

console.log(mathfunc.add(1, 2)); // 3
console.log(mathfunc.subtract(2, 1)); // 1

// This one does not work, will cause an error: 
/// mathfunc.multiply is not a function
console.log(mathfunc.multiply(2, 3)); // 6