# String and fixnum(float) concatenation

**URL:** <https://www.ruby-forum.com/t/string-and-fixnum-float-concatenation/161181>\
**Category:** Ruby\
**Created:** [February 24, 2009, 7:14am UTC](https://www.ruby-forum.com/t/string-and-fixnum-float-concatenation/161181 "2009-02-24T07:14:38Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Jun\_YSKim](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a587f6/32.png) [@Jun\_YSKim](https://www.ruby-forum.com/u/Jun_YSKim)\
**Post date:** [February 24, 2009, 7:14am UTC](https://www.ruby-forum.com/t/string-and-fixnum-float-concatenation/161181/1 "2009-02-24T07:14:38Z")

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hi, forks…

see this source

irb(main):015:0\> puts “%\*s” % [“1”, 2]  
TypeError: can’t convert String into Integer  
from (irb):15:in `%’  
from (irb):15  
from :0  
irb(main):016:0\>

AIK, “%\*s” is to use for concatenation of array.

but, I met the previous error message.

What’s different ways I can take?

---

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**Author:** ![Jun\_YSKim](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a587f6/32.png) [@Jun\_YSKim](https://www.ruby-forum.com/u/Jun_YSKim)\
**Post date:** [February 24, 2009, 7:53am UTC](https://www.ruby-forum.com/t/string-and-fixnum-float-concatenation/161181/2 "2009-02-24T07:53:52Z")

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From: Jun Y. Kim [[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)]  
#…

# AIK, “%\*s” is to use for concatenation of array.

can you point me a link to that info?

afaik, “\*” is used for field widths, eg,

> p “%\*s” % [2,“1”]  
> " 1"

> p “%\*s” % [2,1]  
> " 1"

> p “%.\*s” % [2,“abcdef”]  
> “ab”

---

<div class="post-metadata">

**Author:** ![Jun\_YSKim](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a587f6/32.png) [@Jun\_YSKim](https://www.ruby-forum.com/u/Jun_YSKim)\
**Post date:** [February 24, 2009, 7:59am UTC](https://www.ruby-forum.com/t/string-and-fixnum-float-concatenation/161181/3 "2009-02-24T07:59:44Z")

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From: Peña, Botp [[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)]

# 

# afaik, “\*” is used for field widths, eg,

or precisions

# 

# \> p “%\*s” % [2,“1”]

# " 1"

# 

# \> p “%\*s” % [2,1]

# " 1"

# 

# \> p “%.\*s” % [2,“abcdef”]

# “ab”

# 

also, if just plain concat, %s will do

> puts “%s” % [[“1”, 2]]  
> 12

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<div class="post-metadata">

**Author:** ![Jun\_YSKim](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a587f6/32.png) [@Jun\_YSKim](https://www.ruby-forum.com/u/Jun_YSKim)\
**Post date:** [February 24, 2009, 8:36am UTC](https://www.ruby-forum.com/t/string-and-fixnum-float-concatenation/161181/4 "2009-02-24T08:36:06Z")

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- Jun Y. Kim [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) (07:13) schrieb:

> irb(main):015:0\> puts “%\*s” % [“1”, 2]  
> TypeError: can’t convert String into Integer  
> from (irb):15:in `%’  
> from (irb):15  
> from :0  
> irb(main):016:0\>

Maybe you meant “%\*s” % [2, “1”] if you expect " 1".

mfg, simon … l

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<div class="post-metadata">

**Author:** ![Jun\_YSKim](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a587f6/32.png) [@Jun\_YSKim](https://www.ruby-forum.com/u/Jun_YSKim)\
**Post date:** [February 24, 2009, 8:52am UTC](https://www.ruby-forum.com/t/string-and-fixnum-float-concatenation/161181/5 "2009-02-24T08:52:31Z")

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thanks, wrong knowledge is more worse than wrong action.

1. 
  1. 24, 오후 3:52, Peña, Botp 작성:

> " 1"
> 
> > p “%\*s” % [2,1]  
> > " 1"
> 
> > p “%.\*s” % [2,“abcdef”]  
> > “ab”

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