good morning, afternoon or evening. i was working with a for loop today and something seems to have gone very wrong as this is supposed to create a much larger file than it has nx = 200 ny = 100 touch("image.PPM") open("image.PPM", "w") do image write(image,"P3\n" , string(nx) , " " …

nx is a number; for j in nx iterates once over that number, since numbers in Julia are iterable. You’re looking for for j in 1:nx instead. See also Repeated Evaluation: Loops - Control Flow · The Julia Language Julia provides a variety of control flow constructs: | Documentation for T…

Concerns about this recursive algorithm

New to Julia

ForceBru February 17, 2026, 5:35pm 3

More people looping over integers instead of ranges:

https://discourse.julialang.org/t/i-in-3-is-valid-and-continues-to-cost-me-some-debug-time
https://discourse.julialang.org/t/rant-i-hate-that-its-possible-to-iterate-over-an-integer

3 Likes

Topic		Replies	Views
Question about iterating through a for loop in Julia General Usage question , bug	2	488	December 29, 2020
Question: Why `for n in 10 @show n end` is valid rather than getting error General Usage question	2	400	January 28, 2020
For Loops giving weird results General Usage question	8	1201	January 13, 2018
For loop error? New to Julia	3	536	April 24, 2019
Rant: I hate that it's possible to iterate over an integer New to Julia	41	4026	March 13, 2022

Concerns about this recursive algorithm

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