From: Rajinder Yadav <devguy.ca@...>
Date: 2009-10-23T09:15:24+09:00
Subject: Re: convert/replace a value of nil with 0?

Greg Barozzi wrote:
> Mmcolli00 Mom wrote:
>> Do you know how I can convert or replace any value that gets back a
>> 'nil' to 0?
>>
>> For instance, the myArrayVal[0] may or may not contain a number and I
>> want the code to default to 0 if a nil is returned. I have not found any
>> documentation on this.
> 
> 
> If you want to check each value in an array, try:
> 
> 
> 
> myArrayVal.each_index do |i|
>    myArrayVal[i] = 0 if myArrayVal[i].nil?
> end
> 
> 
> 
> The each_index method allows you to iterate through the array and access 
> each element specifically.
> 
> A less wordy way of writing this would be:
> 
> 
> 
> myArrayVal.each_index do |i|
>    myArrayVal[i] ||= 0
> end
> 
> 
> But using ||= will also convert a value of FALSE to 0, and that may not 
> be a valid operation in your app. Hope this helps and good luck.

Following the examples, if you want to create a new array, you can also do this:

irb(main):001:0> a=[]
irb(main):002:0> a[3]=5
irb(main):003:0> a[6]=12.4
irb(main):004:0> a[7]=22

irb(main):005:0> p a
[nil, nil, nil, 5, nil, nil, 12.4, 22]

irb(main):007:0> b = a.collect { |x| x.nil? ? 0:x }
irb(main):008:0> p b
[0, 0, 0, 5, 0, 0, 12.4, 22]


-- 
Kind Regards,
Rajinder Yadav

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