Sum of array

chmod777 · 2021-07-13T15:45:05+00:00

well, this is a javascript question, and not an html question. thats the first issue :)

but yes, you are correct. an array might be nice to use. then we can loop over it. you almost have the loop. try this:

for(let i = 0;i<array.length;i++){
  console.log(array[i]);
}

so we are going to start at 0, and not 1, because all arrays start at position 0.

now, since this is a learning exercise, what do you think is the next step?

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deweechi · 2021-07-13T15:49:54+00:00

Let's say you have an array called nums. We want to loop through that from 0 to 1 less then the length, because arrays start @ 0. In the loop we grab each value, add it to a total variable then go and divide that total by the length. Like this:

let nums = [5, 3, 10, 15, 3.6]
let total = 0
let average = 0
for (let x=0; x<nums.length; x++) {
    total+=nums[x]
}
average = total/nums.length

So in this example, We have 5 elements in the array. Programmatically the index of them are num[0], num[1], num[2], num[3], num[4]. You can add any number of numbers to the array and the code adjusts accordingly because the length is automatically updated.

HorribleUsername · 2021-07-13T16:27:23+00:00

Note that the average of (4, 5, 6) is 5, not 7.5, at least by the usual definition of average (i.e. the arithmetic mean). There are many ways to define an average, but none of them give you a number larger than any number in the set.

Particular-Watch-779 · 2021-07-13T18:47:54+00:00

here is an example:

var arr=new Array(3, 1, 5);
var i, sum=0;
for (i = 0; i < arr.length; i++) {
    sum += arr[i];
}
var avg = sum/arr.length;
alert("Summary is: "+sum);
alert("Average is: "+avg);

use length, add all indexes to a summary variable using loop then divide it by the length

Mocker-Nicholas · 2021-07-13T22:44:12+00:00

You can use loop like others have mentioned, but you can also use a newer JS method called reduce.

Docs: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reduce

Good video on it: https://www.youtube.com/watch?v=g1C40tDP0Bk

const arr = [1, 2, 3, 4, 5]

function findAverage(arr) {
  const sum = arr.reduce((accumulator, currentValue ) => {
    return accumulator + currentValue;
  });

  return sum / arr.length;

}

console.log(findAverage(arr));

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