Difference between revisions of "Ruby on Rails"
From Hawk Wiki
| Line 1: | Line 1: | ||
| + | <h3>Tutorials</h3> | ||
Beginner's tutorial<br> | Beginner's tutorial<br> | ||
http://allaboutruby.wordpress.com/2006/01/09/installing-rails-on-windows-step-by-step-tutorial/<br> | http://allaboutruby.wordpress.com/2006/01/09/installing-rails-on-windows-step-by-step-tutorial/<br> | ||
| Line 4: | Line 5: | ||
http://www.ruby-lang.org/en/documentation/quickstart/<br> | http://www.ruby-lang.org/en/documentation/quickstart/<br> | ||
| − | <h3>nil? empty? and blank?</h3> | + | <h3>nil?, empty? and blank?</h3> |
.nil? can be used on any object and is true if the object is nil. | .nil? can be used on any object and is true if the object is nil. | ||
| Line 12: | Line 13: | ||
Array length == 0 | Array length == 0 | ||
Hash length == 0 | Hash length == 0 | ||
| + | Running .empty? on something that is nil will throw a NoMethodError. | ||
| + | |||
| + | .blank? will operate on any object | ||
| + | nil.blank? == true | ||
| + | false.blank? == true | ||
| + | [].blank? == true | ||
| + | {}.blank? == true | ||
| + | "".blank? == true | ||
| + | 5.blank? == false | ||
| + | " ".blank? == true | ||
| + | " ".empty? == false | ||
Revision as of 18:08, 16 September 2013
Tutorials
Beginner's tutorial
http://allaboutruby.wordpress.com/2006/01/09/installing-rails-on-windows-step-by-step-tutorial/
Ruby in 20 minutes
http://www.ruby-lang.org/en/documentation/quickstart/
nil?, empty? and blank?
.nil? can be used on any object and is true if the object is nil.
.empty? can be used on strings, arrays and hashes and returns true if:
String length == 0 Array length == 0 Hash length == 0 Running .empty? on something that is nil will throw a NoMethodError.
.blank? will operate on any object nil.blank? == true false.blank? == true [].blank? == true {}.blank? == true "".blank? == true 5.blank? == false " ".blank? == true " ".empty? == false
