Computing the sum and average of elements in an array involves iterating through the array, accumulating the sum of its elements, and then dividing the sum by the total number of elements to get the average. This can be achieved using various techniques, from basic loops to more advanced functional methods provided by JavaScript.

These are the following approaches to computing the sum and average of elements in an array:

Using a for Loop

The simplest way to compute the sum and average is by using a basic for loop to iterate through the array, adding up each element's value to a sum variable, and then dividing by the length of the array to find the average.

Example: This example shows the use of for loop to get the sum and average of an array.

const array = [10, 20, 30, 40, 50];
let sum = 0;

for (let i = 0; i < array.length; i++) {
  sum += array[i]; // Add each element to sum
}

let average = sum / array.length;

console.log("Sum:", sum); 
console.log("Average:", average); 

Sum: 150
Average: 30

Using reduce() Method

The reduce() method executes a reducer function on each element of the array, resulting in a single output value. It's ideal for summing up array values.

Example: This example shows the use of reduce method to get the sum and average of an array.

const array = [10, 20, 30, 40, 50];
const sum = 
   array.reduce((accumulator, currentValue) => accumulator + currentValue, 0);
const average = sum / array.length;

console.log("Sum:", sum); 
console.log("Average:", average);

Sum: 150
Average: 30

Using forEach() Method

The forEach() method executes a provided function once for each array element. You can use it to calculate the sum and then compute the average.

Example: This example shows the use of forEach() method to get the sum and average of an array.

const array = [10, 20, 30, 40, 50];
let sum = 0;

array.forEach((element) => {
  sum += element; // Accumulate sum
});

const average = sum / array.length;

console.log("Sum:", sum);
console.log("Average:", average);

Sum: 150
Average: 30

Using map() and reduce() Methods

The map() method creates a new array populated with the results of calling a provided function on every element in the calling array. You can chain map() with reduce() to get the sum and compute the average.

Example: This example shows the use of map() and reduce() methods to get the sum and average of an array.

const array = [10, 20, 30, 40, 50];
const sum = array.map((element) => element).reduce((acc, curr) => acc + curr, 0);
const average = sum / array.length;

console.log("Sum:", sum); 
console.log("Average:", average); 

Sum: 150
Average: 30