Checking something isEmpty in Javascript?

Question

How can I check if a variable is empty in Javascript? Sorry for the stupid question, but I\'m a newbie in Javascript!

if(response.photo) is empty {
    do so         


        

Answer 1

Here's a simpler(short) solution to check for empty variables. This function checks if a variable is empty. The variable provided may contain mixed values (null, undefined, array, object, string, integer, function).

function empty(mixed_var) {
 if (!mixed_var || mixed_var == '0') {
  return true;
 }
 if (typeof mixed_var == 'object') {
  for (var k in mixed_var) {
   return false;
  }
  return true;
 }
 return false;
}

//   example 1: empty(null);
//   returns 1: true

//   example 2: empty(undefined);
//   returns 2: true

//   example 3: empty([]);
//   returns 3: true

//   example 4: empty({});
//   returns 4: true

//   example 5: empty(0);
//   returns 5: true

//   example 6: empty('0');
//   returns 6: true

//   example 7: empty(function(){});
//   returns 7: false