# Generator Evaluation Order?
**URL:** https://discourse.julialang.org/t/generator-evaluation-order/31823
**Category:** General Usage
**Created:** [December 3, 2019, 9:32pm UTC](https://discourse.julialang.org/t/generator-evaluation-order/31823 "2019-12-03T21:32:29Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@Qiyamah](https://discourse.julialang.org/u/Qiyamah)
#### Post date: [December 3, 2019, 9:32pm UTC](https://discourse.julialang.org/t/generator-evaluation-order/31823/1 "2019-12-03T21:32:29Z")
```nohighlight
julia> fun() = begin
res = 0
map(tuple,
begin
ret = ((a=1/(i+j);res+=a;println("VAL = ",res);a) for i=1:2, j=1:2)
println("RES : ",res)
ret
end,
[1 3; 2 4])
res
end
fun (generic function with 1 method)
julia> fun()
RES : 0
VAL = 0.5
VAL = 0.8333333333333333
VAL = 1.1666666666666665
VAL = 1.4166666666666665
1.4166666666666665
```
why later coming println statement is printed out first? Why is the evaluation order not preserved?
Thanks
---
### Author:  [@yuyichao](https://discourse.julialang.org/u/yuyichao)
#### Post date: [December 3, 2019, 9:43pm UTC](https://discourse.julialang.org/t/generator-evaluation-order/31823/2 "2019-12-03T21:43:48Z")
`ret = ...` just defines the generator, it does not generate anything.
It’s the same reason you won’t get output after evaluating
```julia
f() = println("AAAA")
```
---
### Author:  [@Qiyamah](https://discourse.julialang.org/u/Qiyamah)
#### Post date: [December 3, 2019, 9:48pm UTC](https://discourse.julialang.org/t/generator-evaluation-order/31823/3 "2019-12-03T21:48:11Z")
How do you generate from a generator? what function does map call to activate the generator?
Thanks
---
### Author:  [@yuyichao](https://discourse.julialang.org/u/yuyichao)
#### Post date: [December 3, 2019, 9:51pm UTC](https://discourse.julialang.org/t/generator-evaluation-order/31823/4 "2019-12-03T21:51:21Z")
The generator expression returns something iteratable and you just iterate on it. You can manually call the iterator protocol or us anything that iterates an iterator.
---
### Author:  [@yuyichao](https://discourse.julialang.org/u/yuyichao)
#### Post date: [December 3, 2019, 9:53pm UTC](https://discourse.julialang.org/t/generator-evaluation-order/31823/5 "2019-12-03T21:53:07Z")
Also, if you want to access the result before passing it to map somehow, you should just use a comprehension, which is just a `collect` on the generator.