try {
  let getNumber = () => 42;
  assert(getNumber() === 42);

  let add = (a, b) => a + b;
  assert(add(2, 3) === 5);

  const addBlock = (a, b) => {
    let res = a + b;
    return res;
  };
  assert(addBlock(5, 4) === 9);

  const makeObject = (a, b) => ({ a, b });
  const obj = makeObject(33, 44);
  assert(typeof obj === "object");
  assert(obj.a === 33);
  assert(obj.b === 44);

  let returnUndefined = () => {};
  assert(typeof returnUndefined() === "undefined");

  const makeArray = (a, b) => [a, b];
  const array = makeArray("3", { foo: 4 });
  assert(array[0] === "3");
  assert(array[1].foo === 4);

  let square = x => x * x;
  assert(square(3) === 9);

  let squareBlock = x => {
    return x * x;
  };
  assert(squareBlock(4) === 16);

  const message = (who => "Hello " + who)("friends!");
  assert(message === "Hello friends!");

  const sum = ((x, y, z) => x + y + z)(1, 2, 3);
  assert(sum === 6);

  const product = ((x, y, z) => {
    let res = x * y * z;
    return res;
  })(5, 4, 2);
  assert(product === 40);

  const half = (x => {
    return x / 2;
  })(10);
  assert(half === 5);

  console.log("PASS");
} catch {
  console.log("FAIL");
}