How do you split a long piece of text into separate lines? Why does this return line1 twice?
/^(.*?)$/mg.exec('line1\r\nline2\r\n');
["line1", "line1"]
I turned on the multi-line modifier to make ^ and $ match beginning and end of lines. I also turned on the global modifier to capture all lines.
I wish to use a regex split and not String.split because I'll be dealing with both Linux \n and Windows \r\n line endings.
arrayOfLines = lineString.match(/[^\r\n]+/g);
As Tim said, it is both the entire match and capture. It appears regex.exec(string) returns on finding the first match regardless of global modifier, wheras string.match(regex) is honouring global.
exec returns on first match is because it's intended to be called multiple times for global regexes, until it returns null, and the regex stores things like lastIndex i.e. the index at which to start the next match.
"123\n\n1234".match(/[^\r\n]+/g); expected Array [ "123", "", "1234" ], but got Array [ "123", "1234" ]
Use
result = subject.split(/\r?\n/);
Your regex returns line1 twice because line1 is both the entire match and the contents of the first capturing group.
g flag, and \r is a valid newline on some old apple machines. Also, unicode defines \u2028, \u2029, and the old IBM newline \u0085 as newlines. So /[\n\u0085\u2028\u2029]|\r\n?/g handles all the edge cases.
/g flag? Doesn't make sense to have a split function that only splits once unless explicitly told otherwise. And Jojo said that he's dealing just with Linux and Windows. What next, EBCDIC?
/g flag is not required. You can add it, but JavaScript just ignores it. As Tim said, the default behavior is to split as many times as possible, but you can use the second argument to impose a maximum.(\r\n|[\n\v\f\r\x85\u2028\u2029]), no matter what platform the software runs on, or where the data comes from.g flag controls whether capturing groups are included in the output.I am assuming following constitute newlines
Please Use
var re=/\r\n|\n\r|\n|\r/g;
arrayofLines=lineString.replace(re,"\n").split("\n");
for an array of all Lines including the empty ones.
OR
Please Use
arrayOfLines = lineString.match(/[^\r\n]+/g);
For an array of non empty Lines
\n followed by \r is not a single newline
Even simpler regex that handles all line ending combinations, even mixed in the same file, and removes empty lines as well:
var lines = text.split(/[\r\n]+/g);
With whitespace trimming:
var lines = text.trim().split(/\s*[\r\n]+\s*/g);
Unicode® Technical Standard #18 defines what constitutes line boundaries. That same section also gives a regular expression to match all line boundaries. Using that regex, we can define the following JS function that splits a given string at any line boundary (preserving empty lines as well as leading and trailing whitespace):
const splitLines = s => s.split(/\r\n|(?!\r\n)[\n-\r\x85\u2028\u2029]/)
I don't understand why the negative look-ahead part ((?!\r\n)) is necessary, but that is what is suggested in the Unicode document 🤷♂️.
The above document recommends to define a regular expression meta-character for matching all line ending characters and sequences. Perl has \R for that. Unfortunately, JavaScript does not include such a meta-character. Alas, I could not even find a TC39 proposal for that.
First replace all \r\n with \n, then String.split.
myString.replace(/\r\n/, "\n").split("\n") (unless you are asking because of academic interest :))'line1\r\nline2\r\n'.replace(/\r\n/, '\n').split('\n').without(''); produces a wrong second cell: ["line1", "line2\r"]/g flag for global! It should be: myString.replace(/\r\n/g, "\n").split("\n")replace is a regex.var lines = text.match(/^.*((\r\n|\n|\r)|$)/gm);
I have done something like this. Above link is my fiddle.
