Difference between revisions of "Ruby on Rails"
From Hawk Wiki
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<h3>nil?, empty? and blank?</h3> | <h3>nil?, empty? and blank?</h3> | ||
− | < | + | <pre> |
.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. | ||
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Array length == 0 | Array length == 0 | ||
Hash length == 0 | Hash length == 0 | ||
+ | |||
Running .empty? on something that is nil will throw a NoMethodError. | Running .empty? on something that is nil will throw a NoMethodError. | ||
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" ".blank? == true | " ".blank? == true | ||
" ".empty? == false | " ".empty? == false | ||
− | </ | + | </pre> |
Revision as of 18:10, 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