Questions about vector

New to Julia
,
1 
a=[[1],[1,2],[2,1],[2,5],[111,3],[4,1]]
6-element Vector{Vector{Int64}}:
 [1]
 [1, 2]
 [2, 1]
 [2, 5]
 [111, 3]
 [4, 1]

I want to get the index which of them contain a element named 1,but 111 is not allowed.I want to return [1,2,3,6] .If the sub-vector contains real 1 ,I will return the index. What should I do ? Thanks very much.
findall?

2

I do not know how you want to approach this as a is a vector of vectors.

Though something like this does work:

findall.(x -> x == 1, a)
3 
findall.(x -> x == 1, a)
6-element Vector{Vector{Int64}}:
 [1]
 [1]
 [2]
 [1]
 []
 [2]

Sorry, It cannot return the index. like [1,2,3,6]

1 Like
4 
julia> findall(x -> 1 in x, a)
4-element Vector{Int64}:
 1
 2
 3
 6
4 Likes
5 
julia> findall(1 in v for v in a)
4-element Vector{Int64}:
 1
 2
 3
 6
3 Likes
6

An alternative:

LinearIndices(a)[in.(1, a)]