Difference between revisions of "Ruby on Rails"

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<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>
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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.
  
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Array length == 0
 
Array length == 0
 
Hash length == 0
 
Hash length == 0
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Running .empty? on something that is nil will throw a NoMethodError.
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 +
.blank? will operate on any object
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nil.blank? == true
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false.blank? == true
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[].blank? == true
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{}.blank? == true
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"".blank? == true
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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