printf inside a string

[Peter Bailey]

Hi,
This is a pretty simple question. I need to do a "printf" of some
numbers inside a string. I just can't figure out how to express a long
string that has that "printf" inside it, because the printf statement
itself has quotes, too. I just need the number to end up being
zero-padded to 3 characters. So, for "3," I want "003."

number = "3"

puts "stuff, printf "%.3d\n", #{number}"
...compile error...

Thanks,
Peter

 

[James Edward Gray II]

Hi,
This is a pretty simple question. I need to do a "printf" of some
numbers inside a string. I just can't figure out how to express a long
string that has that "printf" inside it, because the printf statement
itself has quotes, too. I just need the number to end up being
zero-padded to 3 characters. So, for "3," I want "003."

number = "3"

puts "stuff, printf "%.3d\n", #{number}"

stuff, 003
=> nil

Hope that helps.

James Edward Gray II

 

[Alin Popa]

Hi,
This is a pretty simple question. I need to do a "printf" of some
numbers inside a string. I just can't figure out how to express a long
string that has that "printf" inside it, because the printf statement
itself has quotes, too. I just need the number to end up being
zero-padded to 3 characters. So, for "3," I want "003."

number = "3"

puts "stuff, printf "%.3d\n", #{number}"
...compile error...

Thanks,
Peter

Hi Peter,

I don't quite get what are you trying to do, but I advice to do that:

printf("stuff, %.3d\n",number)

That should be all.

Alin.

 

[Oliver VeÄernik]

number = "3"

puts "stuff, printf "%.3d\n", #{number}"
...compile error...

irb(main):001:0> number="3"
=> "3"
irb(main):002:0> printf "stuff, %.3d\n", number
stuff, 003
=> nil
irb(main):003:0> ri "Kernel#sprintf"

 

[ara.t.howard]

stuff, 003
=> nil

Hope that helps.

alternatively

puts "stuff, #{ '%.3d' % number }"


-a

 

[Brian Candler]

This is a pretty simple question. I need to do a "printf" of some
numbers inside a string. I just can't figure out how to express a long
string that has that "printf" inside it, because the printf statement
itself has quotes, too.

I think what you were trying to do is:

number = "3"
puts "stuff, #{sprintf "%.3d", number}"

Note that sprintf(..) is like printf(..) but returns the result as a string
value, rather than sending it to stdout. Then #{} lets you insert an
arbitary expression inside another string.

But as pointed out by others, you can do this in one go as

printf "stuff, %.3d\n", number

HTH,

Brian.

 

[Peter Bailey]

I think what you were trying to do is:

number = "3"
puts "stuff, #{sprintf "%.3d", number}"

Note that sprintf(..) is like printf(..) but returns the result as a
string
value, rather than sending it to stdout. Then #{} lets you insert an
arbitary expression inside another string.

But as pointed out by others, you can do this in one go as

printf "stuff, %.3d\n", number

HTH,

Brian.

Thanks to all you guys. I'll probably use sprintf, actually, now that
I'm clear about how it's used.

Cheers.