isNullOrUndefined

isNullOrUndefined accepts any value and returns true if the value is null or undefined.

For all other values false is returned.

param {Any} any value to test

returns {Boolean} the boolean result of testing value

  isNullOrUndefined(null);   // returns true

  isNullOrUndefined(undefined);   // returns true

  isNullOrUndefined("string");    // returns false

``