In a javascript array, how do I get the last 5 elements, excluding the first element?

You can call:

arr.slice(Math.max(arr.length - 5, 1))

If you don't want to exclude the first element, use

arr.slice(Math.max(arr.length - 5, 0))

Here is one I haven't seen that's even shorter

arr.slice(1).slice(-5)

Run the code snippet below for proof of it doing what you want

var arr1 = [0, 1, 2, 3, 4, 5, 6, 7],
  arr2 = [0, 1, 2, 3];

document.body.innerHTML = 'ARRAY 1: ' + arr1.slice(1).slice(-5) + '<br/>ARRAY 2: ' + arr2.slice(1).slice(-5);

Another way to do it would be using lodash https://lodash.com/docs#rest - that is of course if you don't mind having to load a huge javascript minified file if your trying to do it from your browser.

_.slice(_.rest(arr), -5)

If you are using lodash, its even simpler with takeRight.

_.takeRight(arr, 5);