CODEWITHSUNDEEP
julia
Alex Craft
Alex Craft

Reputation: 15406

Initialise nothing variables in Julia

How to write initialisation for variable that could be nothing in Julia?

id = nothing
title = "Something"
hash  = "31114"

id = id || title || hash # Not working

Upvotes: 3

Views: 1047

Answers (1)

David Sainez
David Sainez

Reputation: 6976

something will return the first value that does not equal nothing. It supports a variable number of arguments:

julia> something(0, nothing)
0

julia> something(nothing, "foo")
"foo"

julia> something(nothing, nothing, 1)
1

You can use it to set the default value for a variable:

x = something(x, DEFAULT_VALUE)

Your example can use:

julia> id = nothing

julia> title = "Something"
"Something"

julia> hash  = "31114"
"31114"

julia> id = something(id, title, hash)
"Something"

Upvotes: 8

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