With Javascript use a for loop to sum numbers in an array

Question

I'm trying to find a way to sum all the numbers that have been added to an array. I believe this should work:

   var total = 0;

   for (var i  = 0; i < totalPrice.length; i++);

   total  += totalPrice[i];
   document.getElementById("displayPrice").innerHTML = total;

But total comes out as a NaN.

This is an example of my code in JSFiddle, if you add the item twice the value gets pushed into the array, what am I doing wrong with the for loop?

https://jsfiddle.net/bgv5s9re/2/

You're welcome. And just FYI, you get `NaN` because `i` is out of bounds, so you're doing `total += undefined`, since out of bounds array access produces the `undefined` value. — , Oct 08 '16 at 15:53
Good point. I misread out of bounds as out of scope. Sorry about that. — Brandon, Oct 08 '16 at 19:42

ScaisEdge · Answer 1 · 2016-10-08T15:59:44.447

4

You could use brackets

  var total = 0;

   for (var i  = 0; i < totalPrice.length; i++){

      total  += totalPrice[i];

   }
   document.getElementById("displayPrice").innerHTML = total;

edited Oct 08 '16 at 15:59

answered Oct 08 '16 at 15:54

ScaisEdge

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While I use that style, it's no more proper than using any other statement. Proper is defined by the spec, and any statement in that position constitutes a proper loop. – Oct 08 '16 at 15:58
1

@squint answer updated – ScaisEdge Oct 08 '16 at 15:59

With Javascript use a for loop to sum numbers in an array

1 Answers1