d3.select.reverse() has no effect

Question

I'm confused why reverse() works for regular arrays but not d3.select objects, which are based on the array as well. I'm basically trying to traverse the elements I selected from the DOM in reverse order via each but the following seem to traverse them in the same order:

d3.selectAll('.someclass').each(function(){console.log(this);})
d3.selectAll('.someclass').reverse().each(function(){console.log(this);})

Answer 1

I figured it out. d3.select IS an array, it's in their documentation ( https://github.com/mbostock/d3/wiki/Selections ), but it's a container array of size 1, the actual array of DOM elements is contained within that first element. The following, while a bit uglier, works as expected:

selection = d3.selectAll('.someclass')
selection[0].reverse()
selection.each(function(){console.log(this);})

I'm not a big fan of using the sort solution (the elements are technically already sorted, and I'd also need to figure out the current order in the DOM tree to compare by).

Answer 2

There is no .reverse() method in D3. Note that selections are not arrays and come with their own implementation of methods to manipulate them. To sort the elements in a particular way, use .sort() .