Quantitative Economics with Julia

for loop in, ∈, =

Below three for loops return the same output. Note that in, ∈, = can be used interchangeably to indicate that i loops over the following array, 1:2:10 which indicates that the array ranges from 1 to 10 with an increment of 2.

for i in 1:2:10
    println(i)
end

for i ∈ 1:2:10
    println(i)
end 

for i = 1:2:10
    println(i)
end 

Output:

1
3
5
7
9

eachindex

I also introduce in this post eachindex, which returns the index of a given vector. Note that the array 1:2:10 has five elements, and i will loop over the five indices with eachindex(1:2:10) .

for i = eachindex(1:2:10)
    println(i)
end 

Output:

1
2
3
4
5

Reference

https://julia.quantecon.org/getting_started_julia/julia_by_example.html