Question

The ruby docs for the String class’s split method state:

[If limit is] negative, there is no limit to the number of fields returned, and trailing null fields are not suppressed.

So as far as I can tell there is no difference between any of the following:

string="1,,2,3,,,4,,5,,6"

string.split(",", -1)
string.split(",", -4)
string.split(",", -1000000)

They all return the same value: ["1", "", "2", "3", "", "", "4", "", "5", "", "6"]

Just wondering why it would be possible to assign different negative limits in this way.

Also, what happens if I do want to remove the trailing null values (like whitespace)? I know I can do string.strip.split(",",-1) but is there a way to do it without using strip method?

Answer 1

By both your testing and your quoted documentation, there appears to be no difference between string.split(",", -1) and string.split(",", -4). The specification says there is no difference and you found no difference in testing. Hooray.

But note that string.strip.split(..) won’t remove the trailing null values:

irb(main):003:0> string="1,,2,3,,,4,,5,,6,,,"
=> "1,,2,3,,,4,,5,,6,,,"
irb(main):004:0> string.split(",", -1)
=> ["1", "", "2", "3", "", "", "4", "", "5", "", "6", "", "", ""]
irb(main):005:0> string.strip.split(",", -1)
=> ["1", "", "2", "3", "", "", "4", "", "5", "", "6", "", "", ""]

You’ll have to pick another mechanism to strip the nulls.