The more I work with R, the more it amazes me. This particular post is about accessing a named component of a list using the component name with the dollar notation
> name$component_name
So if you have a list named assets with two named components, rate_depreciation and rate_exchange, then you can select them by using assets$rate_depreciation and assets$rate_exchange respectively.
What is amazing, is that the component names can also be selected by using the first few letters of the component name – with the minimum number of letters needed to identify them uniquely. So, rate_depreciation component can be selected as:
> assets$rate_d
Similarly, rate_exchange component can be selected as:
> assets$rate_e
This partial-match behavior results from the exact attribute being implicitly set to FALSE in R. If you want R to select only those components that match exactly with the specified component name, you can explicitly set exact=TRUE to alter this behavior:
> name[[component_name, exact=TRUE]]
Now, if you searched for rate_exchange with a shortened name as the selector and exact match flag set, you would get a NULL instead of contents of your named component.
> assets[[rate_e, exact=TRUE]] NULL
Interesting and even nifty, maybe, when you are in a hurry. But, handle with care!
