Three New things in Ruby 1.9.x

There are lot more things improved in Ruby 1.9.2, I am going to discuss about 3 new things I liked which is introduced in Ruby 1.9.x.

Block Variable Scope in Ruby 1.9.x

Block arguments don’t clash with local variables, arguments are always local.
This is a nice fix in Ruby 1.9 .

Ruby 1.8
[source=’ruby’]
check_block = 2
check_block
=> 2
[/source]

[source=’ruby’]
1.upto(5) {|check_block| check_block}
check_block
=> 5
[/source]

Checkout the value of local variable changed to 5, which is clash with the block variable.

Ruby 1.9
[source=’ruby’]
check_block = 2
check_block
=> 2
[/source]
1.upto(5) {|check_block| check_block}
check_block
=> 2

Here the value of check_block is still 2.

New lambda syntax in Ruby 1.9

[source=’ruby’]
lambda =->(a, b){a + b}
lambda.(1,3)
=> 4
[/source]

We can even call the lambda function like
[source=’ruby’]
lambda[2,4]
=> 6
[/source]

It is also possible to give default values for arguments.

[source=’ruby’]
lambda =->(a, b = 10){a + b}
lambda.(1)
=> 11
[/source]
note : Ruby 1.9.2 still supports the older lambda syntax.

New hash Literal

Alternate syntax for Symbol => Object hash notation:

Ruby 1.8
[source=’ruby’]
{:symbol => 10}
=> {:symbol => 10}
[/source]

Ruby 1.9
[source=’ruby’]
{symbol: 10}
=> {:symbol => 10}
[/source]

I will get back to you soon with some additional new things that was in Ruby 1.9.2 .

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Comments (3)

Nice post! I had a similar issue myself with wanting to automate/schedule, create, upload and ping a sitemap.xml so blogged about it here – http://www.geakeit.co.uk/2011/05/12/generating-a-scheduled-google-sitemap-xml-for-your-ecommerce-or-cms-website/. Hopefully someone can find this useful!

nice blog suren

Nice post and thank’s for the useful information.

Thank You,
Uma Mahesh.

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