<p>Say I'm writing some ruby code and I want to use the standard Date type to get the current date. Instead of using a search engine, is there a faster way to find the documentation for this class?  I know I can get the methods for Date by typing <code>Date.methods</code>, but as far as I know this doesn't provide details about argument types or return value.</p>

<p>Editor-specific answers are welcomed.  My editor of choice is Emacs.</p>

On your console use "ri"
```
```
ri Date
```
```
That works with all classes. (e.g. ri String)
To see documentation for a particular method you use this:
```
```
ri Date#yourMethod
```
```