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For loops trouble

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  For loops trouble Daniel Johnson <zaldivar1841@gmail.com> - 2011-04-16 13:27 -0500
    Re: For loops trouble Josh Cheek <josh.cheek@gmail.com> - 2011-04-16 13:36 -0500
      Re: For loops trouble Josh Cheek <josh.cheek@gmail.com> - 2011-04-16 13:38 -0500
    Re: For loops trouble 7stud -- <bbxx789_05ss@yahoo.com> - 2011-04-16 15:10 -0500
    Re: For loops trouble Christopher Dicely <cmdicely@gmail.com> - 2011-04-16 15:30 -0500
    Re: For loops trouble botp <botpena@gmail.com> - 2011-04-16 20:04 -0500

#3019 — For loops trouble

I am trying to translate a program I have in Java into ruby and having
trouble translating this for loop
   for(int i = 0; a[i] < x;i++)
I tried this
   for i in a[i]...x
but it produce some errors. Any help will be appreciated. Thank you.

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

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#3020

[Note:  parts of this message were removed to make it a legal post.]

On Sat, Apr 16, 2011 at 1:27 PM, Daniel Johnson <zaldivar1841@gmail.com>wrote:

> I am trying to translate a program I have in Java into ruby and having
> trouble translating this for loop
>   for(int i = 0; a[i] < x;i++)
> I tried this
>   for i in a[i]...x
> but it produce some errors. Any help will be appreciated. Thank you.
>
> --
> Posted via http://www.ruby-forum.com/.
>
>
numbers = *1..10
max = 6

numbers.each do |num|
  break unless num < max
  puts num
end

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#3021

[Note:  parts of this message were removed to make it a legal post.]

On Sat, Apr 16, 2011 at 1:36 PM, Josh Cheek <josh.cheek@gmail.com> wrote:

> On Sat, Apr 16, 2011 at 1:27 PM, Daniel Johnson <zaldivar1841@gmail.com>wrote:
>
>> I am trying to translate a program I have in Java into ruby and having
>> trouble translating this for loop
>>   for(int i = 0; a[i] < x;i++)
>> I tried this
>>   for i in a[i]...x
>> but it produce some errors. Any help will be appreciated. Thank you.
>>
>> --
>> Posted via http://www.ruby-forum.com/.
>>
>>
> numbers = *1..10
> max = 6
>
> numbers.each do |num|
>   break unless num < max
>   puts num
> end
>


I guess, depending on your needs, you might want the index as well, in which
case

numbers.each do |num|

becomes

numbers.each_with_index do |num, index|

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#3026

Daniel Johnson wrote in post #993238:
> I am trying to translate a program I have in Java into ruby and having
> trouble translating this for loop
>    for(int i = 0; a[i] < x;i++)
> I tried this
>    for i in a[i]...x
> but it produce some errors. Any help will be appreciated. Thank you.

Ruby has a for-in loop:

a = [2, 4, 1, 9, 6]
x = 7

for num in a
  break if num > x
  puts num
end

But a for-in loop calls each(), so ruby programmers just use each() 
directly:

a.each do |num|
  break if num > x
  puts num
end

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

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#3027

On Sat, Apr 16, 2011 at 11:27 AM, Daniel Johnson <zaldivar1841@gmail.com> wrote:
> I am trying to translate a program I have in Java into ruby and having
> trouble translating this for loop
>   for(int i = 0; a[i] < x;i++)
> I tried this
>   for i in a[i]...x
> but it produce some errors. Any help will be appreciated. Thank you.

A simple literal translation goes from this:

for (int i=0; a[i] < x; i++) { ... }

to this Ruby:

i = 0
while a[i] < x
  ...
  i += 1
end

That Ruby is almost certainly not the best way to translate the Java
loop, but the best way really depends on what you are doing in the
loop.

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#3042

On Sun, Apr 17, 2011 at 2:27 AM, Daniel Johnson <zaldivar1841@gmail.com> wrote:
>   for(int i = 0; a[i] < x;i++)

there are many ways.
eg,


> x
=> 6
> a
=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
> a.take_while{|e| e<x}
=> [1, 2, 3, 4, 5]
> a.each_with_index.take_while{|e| e<x}
=> [[1, 0], [2, 1], [3, 2], [4, 3], [5, 4]]

kind regards -botp

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