# Julia: How to set A Random Seed

Hongtao Hao / 2021-07-14

This post is tested under Julia v1.6.1.

In Julia, you can set a random seed using the Random.seed! function. However, keep in mind that you have to use it every time you are using the random number generator.

julia> using Random
julia> Random.seed!(1234)
MersenneTwister(1234)

julia> rand(3)
3-element Vector{Float64}:
0.5908446386657102
0.7667970365022592
0.5662374165061859

julia> rand(3) # Note how the result is different from above
3-element Vector{Float64}:
0.4600853424625171
0.7940257103317943
0.8541465903790502

julia> Random.seed!(1234)
MersenneTwister(1234)

julia> rand(3) # Now the same result combs back
3-element Vector{Float64}:
0.5908446386657102
0.7667970365022592
0.5662374165061859