# Inject problem

**URL:** <https://www.ruby-forum.com/t/inject-problem/192663>\
**Category:** Ruby\
**Created:** [August 3, 2010, 7:55pm UTC](https://www.ruby-forum.com/t/inject-problem/192663 "2010-08-03T19:55:53Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![amiref](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/41988e/32.png) [@amiref](https://www.ruby-forum.com/u/amiref)\
**Post date:** [August 3, 2010, 7:55pm UTC](https://www.ruby-forum.com/t/inject-problem/192663/1 "2010-08-03T19:55:53Z")

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Hi  
In inject method , everytime that inject called what is returned ? for  
example in this code everytime what is returned ?

array = [\*1…10]  
array.inject(0) { | memo , item | memo + item }

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<div class="post-metadata">

**Author:** ![amiref](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/41988e/32.png) [@amiref](https://www.ruby-forum.com/u/amiref)\
**Post date:** [August 3, 2010, 8:24pm UTC](https://www.ruby-forum.com/t/inject-problem/192663/2 "2010-08-03T20:24:56Z")

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On Tue, Aug 3, 2010 at 1:55 PM, Amir E. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> In inject method , everytime that inject called what is returned ? for  
> example in this code everytime what is returned ?
> 
> array = [\*1…10]  
> array.inject(0) { | memo , item | memo + item }

irb(main):001:0\> array = [\*1…10]  
=\> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]  
irb(main):002:0\> array.inject(0) { | memo , item | puts  
“#{memo}\t#{item}”; memo + item }  
0 1  
1 2  
3 3  
6 4  
10 5  
15 6  
21 7  
28 8  
36 9  
45 10  
=\> 55