使用Javascript替换文本中的多个空白行

Question

Hopefully a simple question.

If I have text like this:

Orange
Apples


Melons

Bananas

...how can I replace all occurrences of multiple blank lines with single blank lines, ending up with this:

Orange
Apples

Melons

Bananas

Fiddle: http://jsfiddle.net/Jq4pT/ Need to remove multiple blank lines from the first box's input before inserting into the second.

I've found this link , but am not sure how to use that regular expression in Javascript?

Thanks.

Answer 1

Just use it like this:

var inputString = '...';
var outputString = inputString.replace(/^(\s*\r\n){2,}/, "\r\n")

Answer 2

This is an old question, but I don't care, it comes up first in Google search.

You can do this with the following code:

var EOL = string.match(/\r\n/gm)?"\r\n":"\n";
var regExp = new RegExp("("+EOL+"){3,}", "gm");
string = string.replace(regExp, EOL+EOL);

• First it determines the endline char to use in Regex
• Regex looks for EOL chars being repeated 3 or more times, and replaces them with 2 EOL chars.
• Using g modifier to replace all occurrences
• Using m modifier to apply regex to the whole multi-line string, instead of per line.

Answer 3

Using simple regular expressions:

str = "whatever your string is";
reg = /\n\n\n/;
str.replace(reg, "\n\n");