how to create an array that creates an average javascript code example

Example 1: average of an array js

const avg = arr => {
  const sum = arr.reduce((acc, cur) => acc + cur);
  const average = sum/arr.length;
  return average;
}

console.log(avg([1, 2, 3, 7, 8]));

Example 2: calculate average in javascript

var a = [80, 77, 88, 95, 68];

console.log(eval(a.join('+'))/a.length)