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delete!

delete!(collection, key)

Delete the mapping for the given key in a collection, and return the collection.

Examples

In the Julia programming language, the function delete!(collection, key)

Delete the mapping for the given key in a collection, and return the modified collection.

jldoctest
julia> d = Dict("apple" => 1, "banana" => 2, "orange" => 3);
julia> delete!(d, "banana")
Dict{String,Int64} with 2 entries:
  "apple"  => 1
  "orange" => 3

Provide common examples of its use. If there are any common mistakes users make, add an example.

1. Delete a key-value pair from a dictionary:

   julia> d = Dict("apple" => 1, "banana" => 2, "orange" => 3);
   julia> delete!(d, "banana")
   Dict{String,Int64} with 2 entries:
    "apple"  => 1
    "orange" => 3

   In this example, the key "banana" and its corresponding value 2 are removed from the dictionary d.

2. Modify a dictionary of integers:

   julia> d = Dict(1 => "one", 2 => "two", 3 => "three");
   julia> delete!(d, 2)
   Dict{Int64,String} with 2 entries:
    1 => "one"
    3 => "three"

   It deletes the key 2 and its associated value "two" from the dictionary d.

3. Handle deleting a non-existent key:

   julia> d = Dict("apple" => 1, "banana" => 2, "orange" => 3);
   julia> delete!(d, "grape")
   Dict{String,Int64} with 3 entries:
    "apple"  => 1
    "banana" => 2
    "orange" => 3

   When attempting to delete a key that doesn't exist in the dictionary, delete! returns the original dictionary without any changes.

Common mistake example:

julia> d = Dict("apple" => 1, "banana" => 2, "orange" => 3);
julia> delete!(d, 2)
ERROR: MethodError: no method matching delete!(::Dict{String,Int64}, ::Int64)

In this example, the key provided is of the wrong type (Int64) instead of String. Make sure to use the correct key type matching the dictionary when using delete!.

See Also

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