在Ruby中,我试图写一行,如果已经设置了变量,则使用该变量,否则默认为某个值:
myvar = # assign it to ENV['MY_VAR'], otherwise assign it to 'foobar'
我可以这样写代码:
if ENV['MY_VAR'].is_set? #whatever the function is to check if has been set
myvar = ENV['MY_VAR']
else
myvar = 'foobar'
end
但这相当冗长,我正试图用最简洁的方式来写.我该怎么做?