const subtractNumbers = (a, b) => { return a - b; }; const multiplyNumbers = (a, b) => { return a * b; }; const divideNumbers = (a, b) => { return a / b; }; function calculate(operation, num1, num2) { let result = ''; if (operation == 'add') { result = addNumbers(num1, num2); } else if (operation == 'subtract') { result = subtractNumbers(num1, num2); } else if (operation == 'multiply') { result = multiplyNumbers(num1, num2); } else if (operation == 'divide') { result = divideNumbers(num1, num2); } else { console.log('Invalid operation'); } return res; } const [, , operation, num1, num2] = process.argv; calculate(operation, num1, num2);