Find the sum of all elements in an array consisting of strings and numbers.

textPlusNumberArray.js

function addElements(arr) { 

	// create an array of the alphabet to find the numerical value of each letter in the input array

	let alphabet = ["a", "b", "c", "d", "e", "f", "g", "h", "i",
	 "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u",
	 "v", "w", "x", "y", "z", "A", "B", "C", "D", "E", "F", "G", 
	 "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S",
	 "T", "U", "V", "W", "X", "Y", "Z"];

	let nums = [];                                  // <---- empty array to store the numbers from the input
	let strings = [];                               // <---- empty array to store the strings from the input
	let letterTotal = 0;

	for (let i = 0; i < arr.length; i ++) {         // <---- loop through the input array
		if (isNaN(arr[i])) {                          // <---- if the index is not a number
			strings.push(arr[i])                        // <---- push it into the strings array
		} else {
			nums.push(arr[i])                           // <---- otherwise push it into the numbers array
		}
	}

	nums = nums.reduce((a, b) => a + b, 0);         // <---- use .reduce to add all elements in the numbers array

	strings = strings.toString().split("");         // <---- call the toString method on the strings array, then split it by each letter 
	
	strings.forEach( i => {                         // <---- loop through both the strings array and alphabet
		alphabet.forEach( j => {
			if (i === j) {  		                        // <---- if the letter from the string matches the letter from the alphabet - 
				letterTotal += alphabet.indexOf(i) + 1;   // <---- add the index of that letter to the letter total  
			}																						// <---- since arrays are zero indexed, we add one to each number
		})
	})	
	
	console.log(letterTotal + nums);						    // finally, concatenate both totals and display the result 
}


addElements([1, 'all', 4, 53, 'Cats', 24, 'Bilbo Swaggins', 12, 74, 'Wowwie', 23, 60, 13, 46, 'That is amazing']);