I have to sort through a (rows)array of (row)arrays. The (row)arrays contain an arbitrary number of strings. If a (row)array contains only empty strings I want to remove it from the (rows)array.
I'm currently doing this:
rows.each do |row|
row.each_index do |i|
if row[i].length > 0
break
elsif i == row.count-1
rows.delete(row)
end
end
end
But is there a more elegant way to do it?
Slightly more concise:
rows.reject! { |row| row.all?(&:empty?) }
&expression means "evaluate expression, call to_proc on whatever it returns, and use the value returned by to_proc as the block for this method call". Symbol#to_proc works like this: :method_name.to_proc returns an anonymous function which is just like { |x| x.method_name }.{ |x| x.method }, you can always compress that down to &:method, which should go last in the list of arguments.
Modifying an array while you iterate though it is not a good idea - you may find your code skips certain elements or does weird stuff. I'd do
rows.reject! {|row| row.all? {|row_element| row_element.empty?}}
We reject a row if the block row_element.empty? evaluates to true for all elements in the row. It's well worth getting familiar with all of the methods in Enumerable, they're very handy for this sort of task.
rows.reject{ |row| row.all? &:empty? }when using rails:
! rows.any?(&:present?)
You can use compact.uniq or compact. If your arrays have nil values, compact will result in an empty array, so you can check for that like this:
row.compact.size == 0
if row contains empty strings "" you can check for it like this:
row.compact.uniq.first.blank? and row.size == 1
rows.select{|row| row.compact.count >0}
Here: rows.all?(&:blank?).
