echo if variable is defined in ruby/erb
erb, ruby
Solution
`defined?` is the ruby equivalent to `isset()`.
<%= defined?(a) ? a : 'some default' %>
Problem
Possible Duplicate: Checking if a variable is defined in Ruby using Tilt's template `render` method, I pass in ``` #... t setup ... t.render(self, { :a => 'test', :b => 'again' }) ``` in my `template.erb` ``` <%= a %> <%= b %> ``` say I remove `:b` from the hash that I pass to the template. The render will fail because `:b` is undefined. in PHP, I could go: ``` <?= isset($foo) ? $foo : '' ?> ``` is there any clean way (in ruby/erb) to "echo if"? I tried `<%= b.nil? ? b : '' %>` but that is obviously wrong.. Any help would be appreciated