Convert string arra into array of integers-CodePudding

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

CodePudding user response：

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.

CodePudding user response：

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]]

CodePudding user response：

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

arr = eval(params).flatten(1)

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