Documentation: added example to the function hasfield. (From #41782) (#…

…44274)

Co-authored-by: Johnny Chen <johnnychen94@hotmail.com>
(cherry picked from commit 9c0e5b0d186ea95a06d5b0bdc4bc19d1a17b444d)
(cherry picked from commit aa2421d)

base/reflection.jl

@@ -194,8 +194,23 @@ fieldnames(t::Type{<:Tuple}) = ntuple(identity, fieldcount(t))
 
 Return a boolean indicating whether `T` has `name` as one of its own fields.
 
+See also [`fieldnames`](@ref), [`fieldcount`](@ref), [`hasproperty`](@ref).
+
 !!! compat "Julia 1.2"
      This function requires at least Julia 1.2.
+
+# Examples
+```jldoctest
+julia> struct Foo
+            bar::Int
+       end
+
+julia> hasfield(Foo, :bar)
+true
+
+julia> hasfield(Foo, :x)
+false
+```
 """
 function hasfield(T::Type, name::Symbol)
     @_pure_meta