load vs require

Load

To load a file we use the load method:

load ‘blah.rb’

Note that we must supply the extension when we use it. When Ruby encounters a load, it will read in the contents of the file you’re trying to load. It will do this every time. No matter how many times you load the same feature, Ruby will read the file in every time it encounters a load. You’re not limited to just supplying a name and extension though, you can navigate directories e.g.:

load ‘../../blah.rb’

or even give an absolute path:

load ‘/a/b/c/blah.rb’


Require

No matter how many times you require the same feature in your program, only the first time is significant. Ruby will not re-read a file a second time, this is the first fundamental difference from how load works. The other obvious difference is the fact that you don’t need to supply an extension when you require a feature:

require ‘blah’