Problems with array notation

1

Hello

I’m currently having problems with a personal project. Here is my current JS

$(document).ready(function() {
  console.log('Bonnets');
$('#field').focus();


$('#field').keypress(function(e) {
  var key = (event.keyCode ? event.keyCode : event.which);
  var numbersReactants = [];
  var numbersProducts = [];
  if (key == "13") {
    //Upon enter sign, do an equals check
    var input = $('#field').val();
    if(input.indexOf('=') >= 0) {
      console.log(input);
      var reactants = input.split('=')[0];
      var products = input.split('=')[1];

    //Starts reactants check
    if (reactants.indexOf("+") > 0) {
      reactants = reactants.split("+");
    } else {
      reactants = [reactants];
    }
      for(var i = 0; i<reactants.length; i++) {
        reactants[i] = reactants[i].replace(/\s/g,'');
        if (isNaN(reactants[i][0])) {
          reactants[i] = "1" + reactants[i];
        }
      }
      // Gets numbers

        for (var i = 0; i<reactants.length; i++) {
          $.getJSON("https://enthalpy-api.herokuapp.com/" + reactants[i] + '/', function(result) {
            numbersReactants.push(result);
          });
        }



    //Starts products check
    if (products.indexOf("+") > 0) {
      products = products.split("+");
    } else {
      products = [products];
    }
      for(var i = 0; i<products.length; i++) {
        products[i] = products[i].replace(/\s/g,'');
        if (isNaN(products[i][0])) {
          products[i] = "1" + products[i];
        }
      }

      //Gets products numbers

      for (var i = 0; i<products.length; i++) {
        $.getJSON("https://enthalpy-api.herokuapp.com/" + products[i] + '/', function(result) {
          numbersProducts.push(result);
        });
      }




      //Final Sum


      var productSum = 0;
      for (var i = 0; i<numbersProducts.length; i++) {
        productSum += Number(numbersProducts[i][1]);
      }

      var reactantSum = 0;
      for (var i = 0; i<numbersReactants.length; i++) {
        reactantSum += Number(numbersProducts[i][1]);
      }


      console.log(numbersReactants);
      console.log(numbersProducts);
      console.log("Final Enthalpy: ", (productSum - reactantSum));


      }
    }
});
});

If you look towards the end of the project, the last few lines logs the variables numbersProducts and numbersReactants. The two variables log both fine. See below for a screenshot of the numbersProducts variable under the sample equation N2(g) + 3H2(g) = 2NH3(g). As you can see, it logs just fine, however, if I try to log numbersProducts[0] or anything added onto that, it pulls an error.

image.jpg1438×114 13.4 KB

Do you have any ideas on how I can fix my problem?

2

What is the error? And what do you mean by “try to log numbersProducts[0] or anything added onto that”?

3

@PortableStick

The error just says that the value is undefined even though numbersProducts[0] appears to be defined and then anything added onto that would be something like numbersProducts[0].enthalpy

4

Try moving your console.log calls to the AJAX call you’re making, and make sure it’s the only one:

for (var i = 0; i<products.length; i++) {
        $.getJSON("https://enthalpy-api.herokuapp.com/" + products[i] + '/', function(result) {
          numbersProducts.push(result);
          console.log(numbersProducts[0])
        });
      }
5