Are you talking about the var argument functions or the function which takes definite parameters?

Function with Var Args -

function sum(...numbers) {

  return numbers.reduce((total, number) => total + number, 0);

}

console.log(sum(1, 2, 3, 4, 5)); // Output: 15

Function with 2 Parameters -

function calculateArea(length, width) {

  return length * width;

}

console.log(calculateArea(5, 10)); // Output: 50