Hi, I want to square every element in my array using a block:
a = (1…1000).to_a
a.each {|x| x**2}
But this does not seem to work, it just outputs my array completely
unchanged
Hi, I want to square every element in my array using a block:
a = (1…1000).to_a
a.each {|x| x**2}
But this does not seem to work, it just outputs my array completely
unchanged
Hi –
On Mon, 13 Feb 2006, Jeppe J. wrote:
Hi, I want to square every element in my array using a block:
a = (1…1000).to_a
a.each {|x| x**2}But this does not seem to work, it just outputs my array completely
unchanged
What you want is map, rather than each:
a.map {|x| x**2 }
each just returns the receiver (i.e., the array itself). map returns
a new array, composed of the results obtained by running the block
once for each item.
“collect” is a synonym for map.
David
–
David A. Black ([email protected])
Ruby Power and Light (http://www.rubypowerandlight.com)
“Ruby for Rails” chapters now available
from Manning Early Access Program! http://www.manning.com/books/black
The problem you’re seeing is that :each doesn’t do anything with the
return values of the block.
What you want is :map or :collect (or their destructive forms :map! or
:collect!).
Jeppe J. wrote:
The collect method will produce a new array:
a.collect {|x| x*x}
or, if you want to modify the original array, use collect!
Hi –
On Mon, 13 Feb 2006, Daniel N. wrote:
return values of the block.
What you want is :map or :collect (or their destructive forms :map! or
:collect!).
But probably the methods, not the like-named symbols
David
–
David A. Black ([email protected])
Ruby Power and Light (http://www.rubypowerandlight.com)
“Ruby for Rails” chapters now available
from Manning Early Access Program! http://www.manning.com/books/black
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