Julia is dynamically typed, but you can for performance:
julia> a = [1, 2, 3] # a VectorInt 3-element VectorInt64: 1 2 3 jul-101
julia> sqrt(2) 1.4142135623730951
[deps] DataFrames = "a93c6f00-..." CSV = "736f0a2f-..." Plots = "91a5bcdd-..." Julia is dynamically typed, but you can for