how to find avaige in js code example

Example 1: javascript average of arguments

const average = (...args) => args.reduce((a, b) => a + b) / args.length;

// Example
average(1, 2, 3, 4);    // 2.5

Example 2: calculate average in javascript

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

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