Convert String variable to a List [Groovy]

Question

How can I convert this String variable to a List ?

def ids = "[10, 1, 9]"

I tried with: as List and toList();

But when I do ids.each{println it} I have this result : [ 1 0 , 1 ] — user2068981, Feb 28 '13 at 00:15

score 34 · Accepted Answer · answered Feb 28 '13 at 20:20

34

def l = Eval.me(ids)

Takes the string of groovy code (in this case "[10,1,9]") and evaluates it as groovy. This will give you a list of 3 ints.

answered Feb 28 '13 at 20:20

Rick Mangi

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http://www.jameswiseman.com/blog/2011/01/18/jslint-messages-eval-is-evil/ – Alexander Suraphel Feb 23 '17 at 06:44
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@AlexanderSuraphel Wrong language. – chrylis -cautiouslyoptimistic- Aug 27 '18 at 05:04
@chrylis Meaning? – Alexander Suraphel Aug 31 '18 at 14:54
@AlexanderSuraphel I will answer for him: your article is related to JavaScript (JSLint specifically). But question itself was about Groovy. – Michael A. Jan 13 '19 at 09:46
@MichaelA. Have you read the linked articles? The problem is not specific to JavaScript's Eval. It's the idea of passing a string to a method that is willing to execute anything. I felt that OP needs to know the risks as well. – Alexander Suraphel Jan 14 '19 at 08:26
I think a better link is https://stackoverflow.com/questions/86513/why-is-using-the-javascript-eval-function-a-bad-idea. The ideas discussed apply to any language, not just JavaScript. – Alexander Suraphel Jan 14 '19 at 08:29
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I would not consider using Eval as a safe option though. – Pavol Travnik Feb 28 '20 at 15:34

score 27 · Answer 2 · edited Mar 09 '13 at 03:05

27

def l = ids.split(',').collect{it as int}

edited Mar 09 '13 at 03:05

animuson

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answered Feb 28 '13 at 00:10

Sergio Martinez

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I think you want to make a string "10,1,9" into a list [10,1,9] – Sergio Martinez Feb 28 '13 at 00:17
def id = ids.substring(1,ids.length()-1) def l= id.split(',').collect{it as int} – user2068981 Feb 28 '13 at 00:44
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I find this solution but I don't think is the best : def id = ids.substring(1,ids.length()-1) def l= id.split(',').collect{it as int} – user2068981 Feb 28 '13 at 00:48
this works great for me, specifically in Jenkins, and using String instead of Int: `files = "'f1','f2'" list = files.split(',').collect{it as String} > list==['f1', 'f2'] > list[1]=='f2' ` – Max Cascone Nov 10 '20 at 20:28
updating mine after the edit window closed: `list = versionFile.split(',').collect()` works fine for strings. – Max Cascone Nov 10 '20 at 20:38

Alexander Suraphel · Answer 3 · 2021-11-23T08:19:50.067

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Use the built-in JsonSlurper!

Using Eval is dangerous and the string manipulation solution will fail once the data type is changed so it is not adaptable. So it's best to use JsonSlurper.

import groovy.json.JsonSlurper

//List of ints 
def ids = "[10, 1, 9]"
def idList = new JsonSlurper().parseText(ids)

assert 10 == idList[0]

//List of strings 
def ids = '["10", "1", "9"]'
idList = new JsonSlurper().parseText(ids)

assert '10' == idList[0]

edited Nov 23 '21 at 08:19

answered Apr 16 '15 at 12:41

Alexander Suraphel

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This should definitely be accepted as right answer. – Pavol Travnik Feb 28 '20 at 15:40
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For me with strings this only works when I have : '["string1", "string2"]' and not with "['string1', 'string2']" running the code from jenkins. – herm Nov 22 '21 at 15:01
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@herm tested it myself and you're right. i've updated the answer – Alexander Suraphel Nov 23 '21 at 08:20

score 11 · Answer 4 · answered Mar 23 '19 at 04:56

11

This does work for me. And Eval.me will not work in Jenkins groovy script. I have tried.

assert "[a,b,c]".tokenize(',[]') == [a,b,c]

answered Mar 23 '19 at 04:56

TangHongWan

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`Eval.me` didn't work for me as well (Jenkins groovy script). However, your solution gave a wrong result. My str is "['/a/b/c/d@2/e/f/g/h/i/j/k/l.py::m[n-10-3-9-0/8-17-12]',]" (actually I have more entries in the string, but this is the general idea). The tokenize returns only the inner list, i.e. "[n-10-3-9-0/8-17-12]'" – CIsForCookies Sep 19 '19 at 12:12
The higher scoring answers didn't work for me. This one did. – Vladimir Oct 21 '19 at 13:44

Convert String variable to a List [Groovy]

4 Answers4