Object Methods:

We saw how to call an object on the last page, but of course there are other methods, just as is the case for "strings", Numbers and [arrays]

Below are just a few of them, using our Band object from the last page:

Above, there are again a few things to note:

• typeof :
• typeof Function

When we call the typeof method on the function Band(), we do not include the (). If we do, the result returns undefined.

• typeof new Object()

When we call the typeof method on the new Object(), we can include the () but we don't have to.

• typeof variable

Since new Band() has been assigned as a variable called dogsDamour, if we add () then console alerts us to the fact that a variable is not a function.

• .length

We cannot call .length on the variable itslef. We have to call its key / data values. Or, we can call its .entries

What happens if one of the data values has not been completed?

Lets create a new Object from the Band() function, but lets make it a 3 piece band, which only released a couple of albums:

Now, let's call the .length method again:

The code is telling us that there are 13 keys and 13 data entries. And there are... but some of the data entries are in fact empty "strings" - we can see this if we study carefully the .entries code. But although a computer might read this code perfectly well, it is not very clear to us humans. So let's find a different, better way to get the key / data values: lets use a for... in loop (open console to see the results):

We can also see the results using a for... of loop:

Note the differences in the two loops, and see here for a reminder about their differences.

Object Constructor: