How to create a regular expression for an arbitrary string of numbers, which should be the same and may optionally be separated by a space

Question

I spent about 3 hours trying to create a regular expression to check the coordinate line, which is home (but based on MGRS). I always had a rough time with a regular expression, and it started to make me bang my head on my desk.

Usually I don’t ask for something specific, but none of my friends who are familiar with regular expressions could help, and my own research / attempts to study at this stage drag on for too long.

How can I create a regex to test the following (or is it even possible to do this)?

AZ AA 0123456789 0123456789 HG-20

• All spaces are optional
• The first and second set of 2 characters are case insensitive, but must be az and be 2 characters for each section (first is the grid zone identifier, the second is the subsection identifier).
• The character part to the east and north can be of any arbitrary length if the total number of digits between the two “sections” is equal (for example, “1 1” is valid, “04563213245 54986187995 is really, 5598 549” is invalid). This is the part in which I really do not understand.
• "H" is required, but case insensitive (this is a separator for the height component in the coordinate line)
• "G" is optional (it indicates whether to use the location height or not when converting to Unity coordinates)
• - float, . , .
• . "H", ( , 2 ).

# System.Text.RegularExpressions regex.

, , . , ( , ).

:

/^[a-z]{2}\s?[a-z]{2}\s?\d+\s?\d+\s?hg?[-+]?\d+.?\d+?/ig

, , , ( H... ...).

, , ( InvalidArgument ArgumentOutOfRange, Location). , juju, regex, .

:

• AZ AA 012345 012345 HG-20 ()
• AZAA 012345 012345 HG-20 ()
• AZAA012345012345HG-20 ()
• AZ AA 012345 012345 ()
• AZ AA 012345 01234 (, - ).
• AZ AA 012345 012345 HG (, , "H" )
• AZ AA 012345 012345 H (, , "H" )

!

, - , :

public Location(string coordinateString)
{
    //TODO: Validate string

    //Calling ToUpper() as we never want to worry about casing. Everything is upper case.
    var stripped = coordinateString.ToUpper().Replace(" ", "");
    var gridZonedesignator = stripped.Substring(0, 2);
    var subLocationId = stripped.Substring(2, 2);
    var identifiersRemoved = stripped.Remove(0, 4);
    var heightParsed = identifiersRemoved.Split('H');

    float height = 0;
    bool useGroundHeight = false;

    //If the height component is there, parse ground height flag (if there) and set 
    //height.
    if (heightParsed.Length > 1)
    {
        if (heightParsed[1].StartsWith("G"))
        {
            useGroundHeight = true;
            heightParsed[1] = heightParsed[1].Remove(0);
        }

        height = float.Parse(heightParsed[1], CultureInfo.InvariantCulture);
    }

    //Since the total digits of the easting/northing section must be equal, 
    //simply divide by 2 to separate the number of digits the easting and
    //northing each consist of (accuracy).
    var accuracy = heightParsed[0].Length / 2;

    // It possible to end up with accuracy 1, 2, or 3, in which case we want 
    //to pad 0s to the right as a 1 digit coordinate translates to thousands,
    //not ones as a grid zone is currently 10k x 10k meters.
    //TODO: Base the digits off the scale of a grid zone instead of hard
    //coding to 4. If we change the scale the following will no longer be
    //valid.
    var eastingString = heightParsed[0].Substring(0, accuracy).PadRight(4,'0');
    var northingString = heightParsed[0].Substring(accuracy, accuracy).PadRight(4,'0');

    CoordinateString = coordinateString;
    GridZoneDesignation = gridZonedesignator;
    SubLocationId = subLocationId;
    Easting = eastingString;
    EastingInt = int.Parse(Easting);
    Northing = northingString;
    NorthingInt = int.Parse(Northing);
    IsStartFromGroundHeight = useGroundHeight;
    Height = height;
}

Answer 1

.

• , AZ AA, AZAA, .
  ^(?:[A-Z]{2} ?){2}. ^ anchor , (: non captureing.

• , \d+\s?\d+, - . , . - (?:\d ?\d ?)+ , , , 0 123 01 23, , 0123 0123.
  .NET Regex, . . , . (?'x'\d)+ ?(?'-x'\d)+(?(x)(?!)) regexstorm.

• , . H, G, - + , , : (?:HG?[+-]\d+(?:\.\d+)?)?

^(?:[A-Z]{2} ?){2}(?'x'\d)+ ?(?'-x'\d)+(?(x)(?!)) ?(?:HG?[+-]\d+(?:\.\d+)?)?$

. regexplanet ( .NET) regexstorm.

Answer 2

, . Balanced Groups. #/. Net.

, "N", . N .

^([a-zA-Z]{2}\s?){2}((\d((?>\d(?<N>))*\s?(?>\d(?<-N>))*)*(?(N)(?!))\d))\s?[Hh][Gg]?[-+]?\d+.?\d*

...

^ ([a-zA-Z] {2}\s?) {2} ( ),

(? (\ D (( > \())\S ( > \ (<?? -N > ))) * ((N),())\)?!) x # + + x #

\ ? [Hh] []? H G

[- +]?\d +.?\d * +/- ##. ####

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