isAvgWhole.js

// Create a function that takes an array as an argument and returns true or false depending on whether the average of all elements in the array
// is a whole number or not.
// Examples:
// isAvgWhole([1, 3]) ➞ true
// isAvgWhole([1, 2, 3, 4]) ➞ false
// isAvgWhole([1, 5, 6]) ➞ true
// isAvgWhole([1, 1, 1]) ➞ true
// isAvgWhole([9, 2, 2, 5]) ➞ false

// function isAvgWhole(arr) {
//   return Number.isInteger(arr.reduce((accum, val) => accum + val) / arr.length);
// }
// console.log(isAvgWhole([1, 3]));
// console.log(isAvgWhole([1, 2, 3, 4]));

// Method 2
function isAvgWhole(arr) {
  return !(
    arr.reduce(function (a, b) {
      return a + b;
    }) % arr.length
  );
}
console.log(isAvgWhole([1, 3.1]));

// Method 3
// function isAvgWhole(arr) {
// 	var total = 0;
// 	for(var i =0; i< arr.length; i++){
// 		total = total + arr[i];
// 	}
// 		var ave = total/arr.length;
// 		if(ave % 1 === 0){
// 			return true;
// 		}
// 	else{
// 		return false;
// 	}
// }