# exjl4.jl  example loops and iteration
using Printf

println("julia exjl4.jl running")

for i in 1:5
    print(i, ", ")
end
println() #> 1, 2, 3, 4, 5, 

for i = 1:5       # both "in" and "=" work
    print(i, ", ")
end
println() #> 1, 2, 3, 4, 5, 

arr = [2,4,6,8]
for i in 1:4  # array index starts at 1 like Fortran, Matlab
    print(i, ", ")
end
println() #> 2, 4, 6, 8 


# arrays can also be looped over directly:
a1 = [2,4,6,8]
for i in a1
    print(i, ", ")
end
println() #> 2, 4, 6, 8, 

# continue and break work in loops
a2 = collect(1:20)
for i in a2
    if i % 2 != 0
        continue
    end
    print(i, ", ")
    if i >= 8
        break
    end
end
println() #> 2, 4, 6, 8, 


d1 = Dict(1=>"one", 2=>"two", 3=>"three")
# dicts may be looped through using the keys function:
for k in sort(collect(keys(d1)))
    print(k, ": ", d1[k], ", ")
end
println() #> 1: one, 2: two, 3: three,

# enumerate can be used to get both the index and value in a loop
a3 = ["one", "two", "three"]
for (i, v) in enumerate(a3)
    print(i, ": ", v, ", ")
end
println() #> 1: one, 2: two, 3: three, 


# map works as you might expect performing the given function on each member of an array or iter much like comprehensions
a4 = map((x) -> x^2, [1, 2, 3, 7])
print(a4) #> 4-element Array{Int64,1}: [1,4,9,49]
println(" ")

println("exjl4.jl finished")
# end exjl4.jl