CODEWITHSUNDEEP
javascriptregexcoordinates
plaidshirt
plaidshirt

Reputation: 5701

Validate GPS coordinates with use of regexp

Javascript function get an array as argument, this is input.

var ValidCoordinates = [
    "-23, 25",
    "4, -3",
    "24.53525235, 23.45235",
    "04, -23.234235",
    "0, 1,2",
    "0.342q0832, 1.2324v"
    "43.91343345, 143"
  ];

After that we call function inside a loop certainly:

isValidCoordinates(ValidCoordinates[i])

I have created a function to solve this problem:

function isValidCoordinates(coordinates){
  var args = coordinates.split(",");

  var lat = /^(-?[1-8]?\d(?:\.\d{1,18})?|90(?:\.0{1,18})?)$/;
  var lon = /^(-?(?:1[0-7]|[1-9])?\d(?:\.\d{1,18})?|180(?:\.0{1,18})?)$/;
  //var re = ^[-+]?([1-8]?\d(\.\d+)?|90(\.0+)?),\s*[-+]?(180(\.0+)?|((1[0-7])|([1-9]?\d)(\.\d+)?)$;

  console.log(args[1]);

  if(args[0].match(lat) == true && args[1].match(lon) == true){ 
    return true;
  } else{
    return false;
  }
}

lat and lon variables meet the requirements, I think, but regex match fails always. re is another one regex, that could maybe match all two values.

Upvotes: 1

Views: 1504

Answers (2)

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 627609

You have spaces in between your GPS values, thus, split with the following regex:

var args = coordinates.split(/,\s+/);

The \s+ matches one or more whitespaces. See JS demo:

var ValidCoordinates = [
    "-23, 25",
    "4, -3",
    "24.53525235, 23.45235",
    "04, -23.234235",
   "1, 1,2",
    "43.91343345, 143"
  ];
  
isValidCoordinates(ValidCoordinates[4]);

function isValidCoordinates(coordinates){
  var args = coordinates.split(/,\s+/);

  var lat = /^(-?[1-8]?\d(?:\.\d{1,18})?|90(?:\.0{1,18})?)$/;
  var lon = /^(-?(?:1[0-7]|[1-9])?\d(?:\.\d{1,18})?|180(?:\.0{1,18})?)$/;
  
  console.log("'" + args[0] + "', '" +  args[1] + "'");

  if(lat.test(args[0].trim()) == true && lon.test(args[1].trim()) == true){ 
    console.log("Yes");
  } else{
    console.log("No");
  }
}

Upvotes: 2

Matyas
Matyas

Reputation: 13712

From the point of view understandability I think it would make more sense to parse the values and validate them using number comparison.

var coordsStrings = [
  "-23, 25",
  "4, -3",
  "24.53525235, 23.45235",
  "04, -23.234235",
  "43.91343345, 143",
  "443.91343345, 143",
  "r43.91343345, 143"
];


var coordsNumbers = coordsStrings.map(function(coordsString) {
  return coordsString
    .split(/\s*,\s*/)
    .map(function(coordString) {
      return Number.parseFloat(coordString);
    });
});

// the value of coordsNumbers = [
//   [-23, 25]
//   [4, -3]
//   [24.53525235, 23.45235],
//   [4, -23.234235],
//   [43.91343345, 143]
// ];

// and then your validate logic 
//Latitude = -90 -- +90
//Longitude = -180 -- +180

var isValid = function(coordNumbers) {
  var lat = coordNumbers[0];
  var lng = coordNumbers[1];
  return lat >= -90 && lat <= 90 && lng >= -180 && lng <= 180;
};

for (var i = 0; i < coordsNumbers.length; i++) {
  var v = isValid(coordsNumbers[i]);
  /*...*/
  document.write(coordsNumbers[i][0] + ', ' + coordsNumbers[i][1] + ' is ' + (v ? 'valid':'<strong>invalid</strong>')+'</br>');
}

Upvotes: 1

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