# Repeat loop - how to make it work **URL:** \ **Category:** Gatling (Open-Source)\ **Created:** [January 29, 2022, 8:16am UTC](https://community.gatling.io/t/repeat-loop-how-to-make-it-work/6411 "2022-01-29T08:16:03Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![khiemtang](https://avatars.discourse-cdn.com/v4/letter/k/958977/32.png) [@khiemtang](https://community.gatling.io/u/khiemtang)\ **Post date:** [January 29, 2022, 8:16am UTC](https://community.gatling.io/t/repeat-loop-how-to-make-it-work/6411/1 "2022-01-29T08:16:03Z")
I am trying to get the repeat API to work in my simulation but no matter what I do, I can’t get the HTTP delete call to happen. Inside that repeat loop, I evaluate the URL string, print that out to the console then make the HTTP call. Any idea on how to get this code to work? ![image.png](https://europe1.discourse-cdn.com/flex013/uploads/gatling2/original/1X/409535ce63e6540197ee8024ec8a96b296e770ef.png) What I see printed on the console ![image.png](https://europe1.discourse-cdn.com/flex013/uploads/gatling2/original/1X/3f3e6bef25614220912ce46485b541d5411ab19a.png) Thanks, Khiem ---
**Author:** ![slandelle](https://dub1.discourse-cdn.com/flex013/user_avatar/community.gatling.io/slandelle/32/4_2.png) [@slandelle](https://community.gatling.io/u/slandelle)\ **Post date:** [January 29, 2022, 8:35am UTC](https://community.gatling.io/t/repeat-loop-how-to-make-it-work/6411/2 "2022-01-29T08:35:47Z")
Please read [https://gatling.io/docs/gatling/reference/current/core/concepts/#immutability](https://gatling.io/docs/gatling/reference/current/core/concepts/#immutability) You have to use Gatling DSL components (eg Gatling’s foreach). ![image.png](https://europe1.discourse-cdn.com/flex013/uploads/gatling2/original/1X/409535ce63e6540197ee8024ec8a96b296e770ef.png) ![image.png](https://europe1.discourse-cdn.com/flex013/uploads/gatling2/original/1X/3f3e6bef25614220912ce46485b541d5411ab19a.png) ---
**Author:** ![khiemtang](https://avatars.discourse-cdn.com/v4/letter/k/958977/32.png) [@khiemtang](https://community.gatling.io/u/khiemtang)\ **Post date:** [January 29, 2022, 3:24pm UTC](https://community.gatling.io/t/repeat-loop-how-to-make-it-work/6411/3 "2022-01-29T15:24:02Z")
Thanks, Stephane for the prompt response. I don’t find a lot of information on the foreach loop but managed to change my loop and got “No attribute named ‘list’ is defined”. I may miss something very basic and make the wrong assumption. What is my issue now? ![image.png](https://europe1.discourse-cdn.com/flex013/uploads/gatling2/original/1X/dcbfc344a0da8203c073a8ee44ae075aa9393cc3.png) Thanks, \KT ![image.png](https://europe1.discourse-cdn.com/flex013/uploads/gatling2/original/1X/409535ce63e6540197ee8024ec8a96b296e770ef.png) ![image.png](https://europe1.discourse-cdn.com/flex013/uploads/gatling2/original/1X/3f3e6bef25614220912ce46485b541d5411ab19a.png) ---
**Author:** ![slandelle](https://dub1.discourse-cdn.com/flex013/user_avatar/community.gatling.io/slandelle/32/4_2.png) [@slandelle](https://community.gatling.io/u/slandelle)\ **Post date:** [January 29, 2022, 3:28pm UTC](https://community.gatling.io/t/repeat-loop-how-to-make-it-work/6411/4 "2022-01-29T15:28:42Z")
1. bad session API usage: [https://gatling.io/docs/gatling/reference/current/core/session/session\_api/#setting-attributes](https://gatling.io/docs/gatling/reference/current/core/session/session_api/#setting-attributes) 2. what’s this “foreach().run”??? It should be named “on”, not “run”, see [https://gatling.io/docs/gatling/reference/current/core/scenario/#foreach](https://gatling.io/docs/gatling/reference/current/core/scenario/#foreach) ![image.png](https://europe1.discourse-cdn.com/flex013/uploads/gatling2/original/1X/409535ce63e6540197ee8024ec8a96b296e770ef.png) ![image.png](https://europe1.discourse-cdn.com/flex013/uploads/gatling2/original/1X/3f3e6bef25614220912ce46485b541d5411ab19a.png) ![image.png](https://europe1.discourse-cdn.com/flex013/uploads/gatling2/original/1X/dcbfc344a0da8203c073a8ee44ae075aa9393cc3.png) ---
**Author:** ![khiemtang](https://avatars.discourse-cdn.com/v4/letter/k/958977/32.png) [@khiemtang](https://community.gatling.io/u/khiemtang)\ **Post date:** [January 29, 2022, 6:22pm UTC](https://community.gatling.io/t/repeat-loop-how-to-make-it-work/6411/5 "2022-01-29T18:22:21Z")
Thanks. My latest code below still giving me “[ERROR] i.g.c.s.LoopBlock$ - Condition evaluation crashed with message ‘No attribute named ‘listoflists’ is defined’, exiting loop”. It seems that line 104 has no effect. ```auto 100: }).then (exec 101: { session -> 102: val subLists = session.getList("personaIds").chunked(50) 103: println("subLists:${subLists}") 104: session.set("listoflists", subLists) 105: session 106: }.foreach("#{listoflists}", "list").on( 107: exec { session -> 108: println(session.getList("list")) 109: http("Remove Realm Personas").delete("/v1/personas?ids=${session.getList("list")}") ``` ![image.png](https://europe1.discourse-cdn.com/flex013/uploads/gatling2/original/1X/409535ce63e6540197ee8024ec8a96b296e770ef.png) ![image.png](https://europe1.discourse-cdn.com/flex013/uploads/gatling2/original/1X/3f3e6bef25614220912ce46485b541d5411ab19a.png) ![image.png](https://europe1.discourse-cdn.com/flex013/uploads/gatling2/original/1X/dcbfc344a0da8203c073a8ee44ae075aa9393cc3.png) ---
**Author:** ![slandelle](https://dub1.discourse-cdn.com/flex013/user_avatar/community.gatling.io/slandelle/32/4_2.png) [@slandelle](https://community.gatling.io/u/slandelle)\ **Post date:** [January 29, 2022, 7:51pm UTC](https://community.gatling.io/t/repeat-loop-how-to-make-it-work/6411/6 "2022-01-29T19:51:52Z")
Clearly, you didn’t properly read the documentation. There’s a big warning block exactly explaining your error. ---
**Author:** ![khiemtang](https://avatars.discourse-cdn.com/v4/letter/k/958977/32.png) [@khiemtang](https://community.gatling.io/u/khiemtang)\ **Post date:** [January 30, 2022, 8:42am UTC](https://community.gatling.io/t/repeat-loop-how-to-make-it-work/6411/7 "2022-01-30T08:42:19Z")
Sorry for being ignorant and careless but I couldn’t find the warning that you referred to. Is it related to the use of $ and # to reference a session attribute? I still don’t understand why “#{listoflists}” is not available to the foreach loop. I had “session.set(“listoflists”, subLists)” before the foreach loop. ---
**Author:** ![khiemtang](https://avatars.discourse-cdn.com/v4/letter/k/958977/32.png) [@khiemtang](https://community.gatling.io/u/khiemtang)\ **Post date:** [January 30, 2022, 9:07am UTC](https://community.gatling.io/t/repeat-loop-how-to-make-it-work/6411/8 "2022-01-30T09:07:14Z")
I think I got it now. Session is immutable.