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BorrachApps Mex
Asked: 2020-09-21 11:08:42 +0800 CST 2020-09-21 11:08:42 +0800 CST

Problems generating sums in JavaScript

  • 772

I am making a script that allows me to perform operations to generate the total cost of the products:

  var subtotal = 0;
  var ivaValor = 0;
  var total = 0;
  selected.forEach(function(dato) {
      var pretotal = dato.price * dato.quantity;
      parseFloat(pretotal)
      var total = total + pretotal;

  });
  console.log(total);

But total returns it to me as Not a number (NaN), at the moment I don't understand what happens since total is being declared int.

Note: I'm just starting out in JS :)

javascript

1 Answers

  1. Best Answer

    I couldn't get it to show me NaN but I did notice that you are declaring 2 variables total, one outside the foreach and one inside:

      //...
  var total = 0; // declaracion de variable total
  selected.forEach(function(dato) {
      var pretotal = dato.price * dato.quantity;
      parseFloat(pretotal)
      var total = total + pretotal; // otra vez declarando la variable total

  });
  console.log(total); // imprimes la variable total con el ambito global

    Because of the last line I gather that you want to add the value of the operations dato.price * dato.quantity;to the variable totalinside the foreach. Remove the declaration of the internal total variable from forEachfor the operation to work:

    var selected = [
 {
  price : 44,
  quantity: 2
 },
 {
  price : 20,
  quantity: 1
 }
];

var subtotal = 0;
var ivaValor = 0;
var total = 0;
selected.forEach(function(dato) {
    var pretotal = dato.price * dato.quantity;
    parseFloat(pretotal)
    total = total + pretotal;

});
console.log(total);

    • 3