Node.js - module.exports, require()

/* shape-area.js */
const PI = Math.PI;

// declare and export two functions
function circleArea(r) {
  return PI * r * r;
}
function squareArea(side) {
  return side * side;
}

// then add them as properties to the built-in module.exports object, to make these functions available to other files
module.exports.circleArea = circleArea;
module.exports.squareArea = squareArea;

console.log(circleArea(5));
console.log(squareArea(5));

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/* app.js */

const radius = 5;
const sideLength = 10;

// Option 1: import the entire shape-area.js module here (file path, file name & code from above)
const areaFunctions = require('./shape-area.js');

// Option 2: import circleArea and squareArea with object destructuring - to extract only the needed functions.
//const { circleArea, squareArea } = require("./shape-area.js")

// use the imported .circleArea() and .squareArea() methods here
const areaOfCircle = areaFunctions.circleArea(radius);   //then can use the method imported from the file here
const areaOfSquare =  areaFunctions.squareArea(sideLength);

console.log(areaOfCircle);
console.log(areaOfSquare);