Sometimes when prototyping, we may just need the tags to repeat themselves without any content inside them, so that we create something out of them just through plain css.
ul li li li
With jade you have to write
ul each i in [1, 2, 3] li
What if say, you need an arbitrarily large number of repeating elements?
Instead of writing [1,2,3,4,....]
You can code
ul each i in new Array(10) li
This will get you 10
li elements (but the value of i for every element will be undefined).