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fieldnames

fieldnames(x::DataType)

Get an array of the fields of a DataType.

Examples

julia> struct Person
           name::String
           age::Int
           address::String
       end

julia> fieldnames(Person)
3-element Array{Symbol,1}:
 :name
 :age
 :address

In this example, fieldnames is used to retrieve the field names of the Person struct. The function returns an array of symbols representing the field names (:name, :age, and :address).

julia> struct Point{T}
           x::T
           y::T
       end

julia> fieldnames(Point{Int})
2-element Array{Symbol,1}:
 :x
 :y

Here, fieldnames is called on the Point struct with a specific type parameter Int. It returns an array of symbols representing the fields of the Point{Int} type (:x and :y).

Common mistake example:

julia> fieldnames(2)
ERROR: MethodError: no method matching fieldnames(::Int64)

In this example, fieldnames is called on a non-DataType value (2). The function expects a DataType as an argument, so passing a non-DataType value will result in a MethodError. Make sure to provide a valid DataType to the fieldnames function.

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