From: Mike Stok <mike@...>
Date: 2006-03-22T08:11:03+09:00
Subject: Re: Newbie: Printing hex formatted string using printf


On 21-Mar-06, at 6:03 PM, Wes Gamble wrote:

> In irb, I try to figure out why this doesn't work:
>
> irb(main):001:0> x=3
> => 3
> irb(main):002:0> 3.printf("%X")
> NoMethodError: private method `printf' called for 3:Fixnum
>         from (irb):2
> irb(main):003:0> x.printf("%X")
> NoMethodError: private method `printf' called for 3:Fixnum
>         from (irb):3
> irb(main):004:0>
>
> Why does printf act like a private method here?

Because printf is a method of Kernel

ratdog:~ mike$ irb
irb(main):001:0> x = 3
=> 3
irb(main):002:0> Kernel.printf('%X', x)
3=> nil
irb(main):003:0> 3.methods.include?('printf')
=> false
irb(main):004:0> Kernel.methods.include?('printf')
=> true

Does this help?

Mike

>
> wg
>
> Wes Gamble wrote:
>> I am trying to print the hex representation of a string using printf.
>>
>>   $stderr.print "Magic number is: #{magic_number}.printf('%X')\n"
>>
>> Why does this not work?
>>
>> The output is:
>>
>> Magic number is: %PDF-1.3.printf('%X')
>
>
> -- 
> Posted via http://www.ruby-forum.com/.
>
>

-- 

Mike Stok <mike@stok.ca>
http://www.stok.ca/~mike/

The "`Stok' disclaimers" apply.