KnockoutJS Array

Question

Please checkout this JS Bin http://jsbin.com/iqikuf/3/edit

When the below is run in the console, the result shown makes sense to me.

statement: vd.tools.push(dataItem);
resuelt: 2

But why do we get the below result when run in the console?

statement: vd.tools.length
result: 0

Answer 1

I would like to integrate and explain DCoder's answer.

vd.tools refer to an observableArray which is a Javascript object which lengthproperty does not refer to the amount of stored items.

By "adding the parenthesis" vd.tools() we get a reference to the underlying array which is wrapped by the KnockoutJS's observableArray.

This is the real array which store our data and here we can ask for the length property expecting the correct result.

So then DCoder's answer make perfect sense.

Answer 2

As DCoder pointed out

parentheses needed

vd.tools().length