From: Robert Klemme <shortcutter@...>
Date: 2007-08-18T21:29:58+09:00
Subject: Re: How do you print the first 5 records in an array?

On 18.08.2007 13:14, Konrad Meyer wrote:
> On Saturday 18 August 2007 04:09:16 am Konrad Meyer wrote:
>> On Saturday 18 August 2007 02:55:17 am Bob Sanders wrote:
>>> Let's say I have an array defined as:
>>>
>>> @people = ["Jim", "Jen", "Jess", "Jay", "Jack", "John", "Jeff", "Jed",
>>> "Jill"]
>>>
>>> How would I then print out the first 5 records of that array? (i.e. from
>>> Jim to Jack)
>>>
>>> Any ideas?
>> One idea comes to mind:
>>
>>   @people.inject([]){|a,p|a<<p if a.length<5;a}.each{|p|puts p}
> 
> Actually:
> 
>   $><<@people.inject([]){|a,p|a<<p if a.length<5;a}*"\n"

Although I'm always fond of solutions using #inject in this case I'm 
sorry to say that but this is not only inefficient but totally 
obfuscated.  If you feel you have to iterate then you can immediately 
print members.  These are my preferred solutions

# fast and readable
5.times {|i| puts @people[i]}
0.upto(4) {|i| puts @people[i]}

# might be less efficient but
# very readable
puts @people[0,5]
puts @people[0...5]
puts @people[0..4]

Note: it's not too unlikely that those variants with the sub arrays are 
actually faster, because that is all done in C code.

Cheers

	robert