Ruby concatenate strings and add spaces

I have 4 string variables name, quest, favorite_color, speed that might be empty. I want to concatenate them all together, putting spaces between those that aren't empty. Simplicity of the code, i.e how simple is to to look at and understand, is more important than speed.

So:

name = 'Tim'
quest = 'destroy'
favorite_color = 'red'
speed = 'fast'

becomes

'Tim destroy red fast'

and

name = 'Steve'
quest = ''
favorite_color = ''
speed = 'slow'

becomes:

'Steve slow'

Note there is o开发者_JAVA技巧nly 1 space between 'Steve' and 'slow'.

How do I do that (preferably in 1 line)?

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[name, quest, favorite_color, speed].reject(&:empty?).join(' ')

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Try [name,quest,favorite_color,speed].join(' ').squeeze(' ')

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You can use inject:

[name,quest,favorite_color,speed].inject("") {|k,v| v.empty? ? k : k << " " << v }.strip