Upcase array

[Fredrik Jagenheim]

Given this array:
foo = %w { FOO BAR baz biz }

How do I make all the entries uppercase in a short and readable way?

The (to me) obvious solution won't work:
foo.map! { |x| x.upcase! }
as upcase returns nil if it doesn't have anything to upcase...

//F

 

[Thomas Leitner]

On Wed, 6 Oct 2004 17:41:50 +0900

| Given this array:
| foo = %w { FOO BAR baz biz }
|
| How do I make all the entries uppercase in a short and readable way?
|
| The (to me) obvious solution won't work:
| foo.map! { |x| x.upcase! }
| as upcase returns nil if it doesn't have anything to upcase...
|
| //F
|
|

Do not use x.upcase! but x.upcase (without the exclamation mark):

irb(main):005:0> foo = %w{ FOO BAR baz biz }
=> ["FOO", "BAR", "baz", "biz"]
irb(main):006:0> foo.map! { |x| x.upcase }
=> ["FOO", "BAR", "BAZ", "BIZ"]

*hth*,
Thomas

 

[Robert Klemme]

On Wed, 6 Oct 2004 17:41:50 +0900

| Given this array:
| foo = %w { FOO BAR baz biz }
|
| How do I make all the entries uppercase in a short and readable way?
|
| The (to me) obvious solution won't work:
| foo.map! { |x| x.upcase! }
| as upcase returns nil if it doesn't have anything to upcase...
|
| //F
|
|

Do not use x.upcase! but x.upcase (without the exclamation mark):

irb(main):005:0> foo = %w{ FOO BAR baz biz }
=> ["FOO", "BAR", "baz", "biz"]
irb(main):006:0> foo.map! { |x| x.upcase }
=> ["FOO", "BAR", "BAZ", "BIZ"]

Even more efficient is the usage of #each and #upcase!

foo = %w{ FOO BAR baz biz } => ["FOO", "BAR", "baz", "biz"]
foo.each {|s| s.upcase!} => ["FOO", "BAR", "BAZ", "BIZ"]

Here, no new instances are created.

Regards

robert

 

[Bill Atkins]

Why does upcase! do this?