regex for matching latitude, longitudes without any character

user_10213385 0
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I am looking for one regex which strictly allows 2 floating point numbers which are comma separated.

Test cases:

0,0
0.021312311323,0
0,0.012312312312
1.1,0.9836373

Regex that I have tried is

^[-+]?([1-8]?\d(\.\d+)?|90(\.0+)?),\s*[-+]?(180(\.0+)?|((1[0-7]\d)|([1-9]?\d))(\.\d+)?)$\D+|\d*\.?\d+

These are latitudes and longitudes but I just want 2 values in these paremeters.

This regex fails in:

-10a, 10a
10a,10b

I would really appreciate any help and guidance.

regex
2 Answers

Your regex ends with a couple of redundant patterns, you should remove \D+|\d*\.?\d+ after $. As $ means the end of string, there can be no more text after it, and the \D+|\d*\.?\d+ requires one or more non-digit chars, or just matches any float or integer number with \d*\.?\d+ - this matched your unwelcome strings.

You can use

^([-+]?(?:[1-8]?\d(?:\.\d+)?|90(?:\.0+)?)),\s*([-+]?(?:180(?:\.0+)?|(?:1[0-7]\d|[1-9]?\d)(?:\.\d+)?))$

See the regex demo. Note I converted some capturing groups into non-capturing, so that there remain just two "notional" capturing groups in the pattern.

Details

  • ^ - start of string
  • ([-+]?(?:[1-8]?\d(?:\.\d+)?|90(?:\.0+)?)) - Group 1:
    • [-+]? - an optional - or +
    • (?:[1-8]?\d(?:\.\d+)?|90(?:\.0+)?) - either a number from 0 to 89 ([1-8]?\d) and then an optional fractional part ((?:\.\d+)?) or 90 and then an optional . followed with one or more 0 chars
  • ,\s* - a comma and 0+ whitespace chars
  • ([-+]?(?:180(?:\.0+)?|(?:1[0-7]\d|[1-9]?\d)(?:\.\d+)?)) - Group 2:
    • [-+]? - an optional - or +
    • (?:180(?:\.0+)?|(?:1[0-7]\d|[1-9]?\d)(?:\.\d+)?) - either a 180 number followed with an optional . + one or more 0 chars, or a number from 0 to 179 and then an optional fractional part
  • $ - end of string.
user_38329700

Your regular expression is almost correct. You should have stopped at $ indicating the end of the string.

const testCases = [ "0,0",
                    "0.021312311323,0",
                    "0,0.012312312312",
                    "1.1,0.9836373",
                    "-10a, 10a",
                    "10a,10b"];

const re = /^[-+]?([1-8]?\d(\.\d+)?|90(\.0+)?),\s*[-+]?(180(\.0+)?|((1[0-7]\d)|([1-9]?\d))(\.\d+)?)$/g;


testCases.forEach(tc => {
  if(tc.match(re)) {
    console.log("    VALID : " + tc );
  } else {
    console.log("NOT VALID : " + tc);
  }
});

user_7361720
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