samlerepo/Code/6.dicts.jl

46 lines
1.2 KiB
Julia

# Dicts (dictionaries/maps) are not as simple as in python, resembling
# more the way modern c++ does it
# Dicts are usually created from an array of "Pair" types (First => Last)
# The type of the dict keys and values are automatically infered.
d = Dict([
"foo" => 3,
"bar" => 7
])
display(d)
# A dict can also be initialized as an array of two tuples. This works
# identically to the example above
d = Dict([
("foo", 2.71),
("bar", 3.14)
])
display(d)
# Values can be pushed to the dict similarly to an array.
# Keep in mind that creating an empty dict like this gives the type
# Dict{Any, Any} which might be somewhat slower because of having
# to work for general types
d = Dict()
push!(d, "foo" => 1//2)
push!(d, "bar" => 22//7)
display(d)
# The problem above can be mitigated by infering the types manually
d = Dict{String, Rational{Int}}()
push!(d, "foo" => 1//2)
push!(d, "bar" => 22//7)
display(d)
# A key can be deleted from a dict with delete!()
delete!(d, "foo")
display(d)
# To check if a certain key exists in the dict, the haskey function is used
println(haskey(d, "foo")) # false
println(haskey(d, "bar")) # true
# Indexing a dict is done with brackets like for any array
println(d["bar"])