hogehoge.jl

function hoge(number)
    if number == 1 
        f() = "1"
    elseif number == 2
        f() = "2"
    end 
    return f
end

f = hoge(1)
println(f()) # 2

hoge(2) # ERROR: UndefVarError: f not defined

hogehoge2.jl

function hoge(number)
    if number == 1 
        f() = 1
        x   = 1
    elseif number == 2
        f() = 2
        x   = 2
    end 
    return f,x
end

f,x = hoge(1)
println(f()) # 2
println(x)   # 1

hoge(2) # ERROR: UndefVarError: f not defined

hogehoge3.jl

function hoge(number)
    if number == 1 
        f() = 1
        println(1)
    elseif number == 2
        f() = 2
        println(2)
    end 
    return f
end

f = hoge(1)  # 1
println(f()) # 2

f = hoge(2)  # 2
             # # ERROR: UndefVarError: f not defined