How to find no of attributes in JSON

function jsonVarCount() {

  var x = {
    hello:function() {
      alert('hello world');
    },
    foo: 'bar'
  }
  var y = [function() {
      alert('hello world');
    },'foo','bar']

  var xCount = 0;
  for(var a in x) xCount++;
  var yCount = 0;
  for(a in y) yCount++;
  alert(xCount+','+yCount)

}

  var y = ['foo','bar'];
  for(var a in y) alert(a+' : '+y[a]);