CODEWITHSUNDEEP
javascriptarrayssum
George Munteanu
George Munteanu

Reputation: 3

Sum of Array - JS

I'm following a coursera course and I'm a bit stuck on a line of code. I understand what it does but not why. The video explains how to get the avarage value of an Array.

I found this code online and its exactly the part that I don't get:

var numbers = [10, 20, 30, 40] // sums to 100
var sum = 0;
for (var i = 0; i < numbers.length; i++) {
  sum += numbers[i]
}

I don't get this part:

sum+=numbers[i]

I read it as sum = 0+4.

What am I missing?

Upvotes: 0

Views: 118

Answers (2)

Siva Kondapi Venkata
Siva Kondapi Venkata

Reputation: 11001

In sum += numbers[i], with operator += means sum = sum + numbers[i]

Upvotes: 0

anpel
anpel

Reputation: 941

Basically what is says is "take whatever is in the i position of the numbers and add it to the value of sum".

So for example, if i = 2, then "whatever is in the i position of numbers would be 30.

To elaborate further, var numbers = [10, 20, 30, 40] can also be written as:

var numbers = [];
numbers[0] = 10;
numbers[1] = 20;
numbers[2] = 30;
numbers[3] = 40;

Hope this helps you understand better.

Upvotes: 2

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