function calculate(expression) {
    try {
        let result = eval(expression);
        if (isNaN(result)) {
            throw new Error("Invalid expression");
        }
        return result;
    } catch (e) {
        return "Error: " + e.message;
    }
}

let userInput = prompt("Enter an arithmetic expression (for example, 2 + 2):");

if (userInput !== null) {
    console.log("Result:", calculate(userInput));
}

const createCounter = () => {
  let count = 0;
  return () => {
    console.log(count++);
  };
};

const counter1 = createCounter();
const counter2 = createCounter();

counter1(); 
counter2();

function greet(name) {
  console.log("Hello, " + name);
}

greet();

const data = [1, 2, 3, 4, 5];

function getEvenNumbers(arr) {
  return arr.filter(num => num % 2 = 0);
}

console.log(getEvenNumbers(data));