Question

How would I split a javascript string such as foo\nbar\nbaz to an array of lines, while preserving the newlines? I’d like to get ['foo\n', 'bar\n', 'baz'] as output;

I’m aware there are numerous possible answers – I’m just curious to find a stylish one.

With perl I’d use a zero-width lookbehind assertion: split /(?<=\n)/, but they are not supported in javascript regexs.

PS. Extra points for handling different line endings (at least \r\n) and handling the missing last newline (as in my example).

Answer 1

You can perform a global match with this pattern: /[^\n]+(?:\r?\n|$)/g

It matches any non-newline character then matches an optional \r followed by \n, or the end of the string.

var input = "foo\r\n\nbar\nbaz";
var result = input.match(/[^\n]+(?:\r?\n|$)/g);

Result: ["foo\r\n", "bar\n", "baz"]