Convert string arra into array of integers

Question

I am receiving params like this "[[201], [511], [3451]]", I want to convert it into [201, 511, 3451]

I think the link below will help you. https://stackoverflow.com/questions/9593765/convert-array-values-from-string-to-int — Göksel Doğan, Oct 14 '21 at 23:12
[I think the link below will help you.](https://stackoverflow.com/questions/9593765/convert-array-values-from-string-to-int) — Göksel Doğan, Oct 14 '21 at 23:13

Gameza · Answer 1 · 2021-10-15T04:47:42.467

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Let's say params is what you're receiving, you can use scan and map to use a Regular Expression, look for the digits in the response and then map each item in the array to an integer:

params = "[[201], [511], [3451]]"
params_array = params.scan(/\d+/).map(&:to_i)

What we are doing here is we are looking through the string and selecting only the digits with the Scan method, afterwards we get a string array so to convert it into integers we use the Map method. As per the map method, thanks to Cary Swoveland for the update on it.

edited Oct 15 '21 at 04:47

answered Oct 14 '21 at 23:56

Gameza

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Great observation @CarySwoveland, editing – Gameza Oct 15 '21 at 04:44
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No attribution is needed. Incidentally, to keep your answers "clean", if you want to make an attribution I suggest you do it in a comment. – Cary Swoveland Oct 15 '21 at 05:36

score 1 · Answer 2 · answered Oct 15 '21 at 09:37

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It will help you!

str_arr = "[[201], [511], [3451]]"

JSON.parse(str_arr).flatten

or

eval(str_arr).flatten

answered Oct 15 '21 at 09:37

Edil Talantbekov

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6

Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers [in the help center](/help/how-to-answer). – Community Oct 15 '21 at 10:08

score 0 · Answer 3 · answered Oct 15 '21 at 03:22

0

here is an interesting way (note that it only works in case your params is an array string)

arr1 = instance_eval("[1,2,3]")
puts arr1.inspect # [1,2,3]

arr2 = instance_eval("[[201], [511], [3451]]")
puts arr2.inspect # [[201], [511], [3451]]

answered Oct 15 '21 at 03:22

Lam Phan

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You could use `p` instead of writing `puts` with `inspect` – Rajagopalan Oct 15 '21 at 03:25
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Note the Rails tag and the use of the word _params_ which implies form data sent by the user agent. Doing this will allow the HTTP client to evaluate arbitrary Ruby code on the server. – Matheus Moreira Oct 15 '21 at 06:14
@LamPhan : Why `instance_eval` and not `eval`? – user1934428 Oct 15 '21 at 06:53
@user1934428 when i answered this question i even haven't thought about security, so `instance_eval` here is used for some cases the input array string maybe contains some specific values of the instance of the invoke class such as "[X, Y, Z]". – Lam Phan Oct 15 '21 at 07:21

score 0 · Answer 4 · answered Oct 15 '21 at 07:12

First, I would make a sanity check that you don't get malevolent code injected:

raise "Can not convert #{params}" if /[^\[\]\d]/ =~ params

Now you can assert that your string is safe:

params.untaint

and then convert

arr = eval(params).flatten

or

arr = eval(params).flatten(1)

depending on what exactly you want to receive if you have deeply-nested "arrays" in your string.

Convert string arra into array of integers

4 Answers4