Removing all whitespace lines from a multi-line string efficiently

Question

In C# what\'s the best way to remove blank lines i.e., lines that contain only whitespace from a string? I\'m happy to use a Regex if that\'s the best solution.

EDIT

Answer 1

not good. I would use this one using JSON.net:

var o = JsonConvert.DeserializeObject(prettyJson);
new minifiedJson = JsonConvert.SerializeObject(o, Formatting.None);

Answer 2

In response to Will's bounty here is a Perl sub that gives correct response to the test case:

sub StripWhitespace {
    my $str = shift;
    print "'",$str,"'\n";
    $str =~ s/(?:\R+\s+(\R)+)|(?:()\R+)$/$1/g;
    print "'",$str,"'\n";
    return $str;
}
StripWhitespace("test\r\n \r\nthis\r\n\r\n");

output:

'test

this

'
'test
this'

In order to not use \R, replace it with [\r\n] and inverse the alternative. This one produces the same result:

$str =~ s/(?:(\S)[\r\n]+)|(?:[\r\n]+\s+([\r\n])+)/$1/g;

There're no needs for special configuration neither multi line support. Nevertheless you can add s flag if it's mandatory.

$str =~ s/(?:(\S)[\r\n]+)|(?:[\r\n]+\s+([\r\n])+)/$1/sg;

Answer 3

char[] delimiters = new char[] { '\r', '\n' };
string[] lines = value.Split(delimiters, StringSplitOptions.RemoveEmptyEntries);
string result = string.Join(Environment.NewLine, lines)

Answer 4

if its only White spaces why don't you use the C# string method

    string yourstring = "A O P V 1.5";
    yourstring.Replace("  ", string.empty);

result will be "AOPV1.5"

Answer 5

String Extension

public static string UnPrettyJson(this string s)
{
    try
    {
        // var jsonObj = Json.Decode(s);
        // var sObject = Json.Encode(value);   dont work well with array of strings c:['a','b','c']

        object jsonObj = JsonConvert.DeserializeObject(s);
        return JsonConvert.SerializeObject(jsonObj, Formatting.None);
    }
    catch (Exception e)
    {
        throw new Exception(
            s + " Is Not a valid JSON ! (please validate it in http://www.jsoneditoronline.org )", e);
    }
}

Answer 6

Here is something simple if working against each individual line...

(^\s+|\s+|^)$