title: Knockout get object from observableArray
body: <p>I have an observableArray in my Knockout app and I'm wondering how I can go about selecting only the targeted object within the array.</p>
  
  <p>I have the following code which calculates the total of all 'value's within the array but I'd like to be able to just select, say, only the second 'value' within the array.</p>
  
  <pre><code>self.csu_treatment_inputs = ko.observableArray([
                  {
                      value: ko.observable(10),
                      image: ko.observable('')
                  },
                  {
                      value: ko.observable(120),
                      image: ko.observable('')
                  },
                  {
                      value: ko.observable(160),
                      image: ko.observable('')
                  },
  
              ]);
  
  self.totaltest = ko.computed(function () {
              var total = 0;
              ko.utils.arrayFilter(self.value_inputs(), function (item) {
                    total += parseFloat(ko.utils.unwrapObservable(item.value));
              });
              return total;
      });
  </code></pre>