Suppose I have a dictionary declared like this:
g:dict = {
\ 'foo' : ['foobar'],
\ 'bar' : ['barfoo']
\}
how can I get the key for barfoo using just the value(barfoo) itself?
asked Nov 13, 2018 at 3:34
2 Answers
There's no function to get a dictionary key from a value, so you'll have to loop over the keys. For example:
for [key, value] in items(g:dict)
if index(value, "barfoo") >= 0
let g:mykey = key
break
endif
endfor
echo g:mykey
echo keys(filter(copy(dict), 'index(v:val, "foobar")>=0'))[0] should do it
Note it'll be much more efficient than a loop
answered Nov 13, 2018 at 7:32
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1you might want to
copythe dict to prevent it from being changed accidentally Nov 13, 2018 at 7:38 -
@ChristianBrabandt but if you copy it, it would no longer be more efficient than simply looping over it, right?– muruNov 13, 2018 at 7:47
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1@ChristianBrabandt how so? If the goal is to prevent accidental modification, you'd need a full deep copy, and that cannot be faster than simply iterating over a view of those items.– muruNov 13, 2018 at 8:05
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Even after a copy it s usually faster. Loops are really slow :(. Thanks for the reminder, i'll fix my answer Nov 13, 2018 at 10:49
barfoo?