phpjs/functions/var/is_int.js

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function is_int(mixed_var) {
  //  discuss at: http://phpjs.org/functions/is_int/
  // original by: Alex
  // improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // improved by: WebDevHobo (http://webdevhobo.blogspot.com/)
  // improved by: Rafał Kukawski (http://blog.kukawski.pl)
  //  revised by: Matt Bradley
  // bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  //        note: 1.0 is simplified to 1 before it can be accessed by the function, this makes
  //        note: it different from the PHP implementation. We can't fix this unfortunately.
  //   example 1: is_int(23)
  //   returns 1: true
  //   example 2: is_int('23')
  //   returns 2: false
  //   example 3: is_int(23.5)
  //   returns 3: false
  //   example 4: is_int(true)
  //   returns 4: false

  return mixed_var === +mixed_var && isFinite(mixed_var) && !(mixed_var % 1);
}