String comparisions and counting

Ruby
1

I have an array full of strings which represent a date ID. The array
contains indivduals strings like the following:

TueAug052008

I want to iterate through this array (@eventbydate[]) and check each of
the values of the array. I then want a statement which says if any of
the date ID’s in the array occurs more than 5 times print out some data.

Pseudo code

if dataID occurs more than 5times
print results
end

I hope this makes sense.

I would appreciate any help

Regards

2

On Wed, Nov 5, 2008 at 7:35 AM, Stuart C.
[email protected] wrote:

if dataID occurs more than 5times
print results
end

I hope this makes sense.

I would appreciate any help

Regards

[1, 1, 2, 3, 4].count(1)

Todd

3

Stuart C. wrote:

I have an array full of strings which represent a date ID. The array
contains indivduals strings like the following:

TueAug052008

I want to iterate through this array (@eventbydate[]) and check each of
the values of the array. I then want a statement which says if any of
the date ID’s in the array occurs more than 5 times print out some data.

counts = Hash.new(0)
@eventbydate.each { |e| counts[e] += 1 }
if counts.find { |c| c >= 5 }
puts “Print out some data”
end

There are other variations:

…
if counts.values.max >= 5
…

More efficient is to stop counting as soon as you reach 5, if you don’t
need the final values:

counts = Hash.new(0)
if @eventbydate.find { |e| (counts[e] += 1) >= 5 }
puts “Print out some data”
end

4

On Wed, Nov 5, 2008 at 10:35 PM, Stuart C.

5

Oops:

if counts.find { |c| c >= 5 }

if counts.find { |k,v| c >= 5 }

6

On Wed, Nov 5, 2008 at 10:35 PM, Stuart C.
[email protected] wrote:

Posted via http://www.ruby-forum.com/.

Is this helpful?

arr = [“a”,“b”,“a”,“c”,“a”,“a”,“c”]

h = Hash.new(0)
arr.each {|x| h[x] += 1}
h.each {|x,y| p x if y > 3}

Harry

7

Great stuff thanks. I went the last solution as I only want to pick up
any any high occurances.

Many thanks

Brian C. wrote:

Stuart C. wrote:

I have an array full of strings which represent a date ID. The array
contains indivduals strings like the following:

TueAug052008

I want to iterate through this array (@eventbydate[]) and check each of
the values of the array. I then want a statement which says if any of
the date ID’s in the array occurs more than 5 times print out some data.

counts = Hash.new(0)
@eventbydate.each { |e| counts[e] += 1 }
if counts.find { |c| c >= 5 }
puts “Print out some data”
end

There are other variations:

…
if counts.values.max >= 5
…

More efficient is to stop counting as soon as you reach 5, if you don’t
need the final values:

counts = Hash.new(0)
if @eventbydate.find { |e| (counts[e] += 1) >= 5 }
puts “Print out some data”
end

8

On Wed, Nov 5, 2008 at 8:18 AM, Brian C. [email protected]
wrote:

counts = Hash.new(0)

More efficient is to stop counting as soon as you reach 5, if you don’t
need the final values:

counts = Hash.new(0)
if @eventbydate.find { |e| (counts[e] += 1) >= 5 }
puts “Print out some data”
end

Pretty darn good. Why not use a database? I guess it comes down to
often you want to query the data.

Todd