Summarize JSON

gistfile1.js

var sum = function(o, tabLevel){
  for(var prop in o){
    if(o.hasOwnProperty(prop)){
      var val = o[prop];
      var header = "";
      for( var t = 0; t < tabLevel; t++ )
      {
        header += '\t';
      }
      console.log(header + prop + ":");
      if(typeof val == 'object'){
        sum(val, tabLevel+1);
      }
    }
  }
};

sum({ 'foo':'bar', biz: { x: 'y', nested: { z: [1,2,3,4] } } }, 0);

Output:

foo:
biz:
    x:
    nested:
        z:
            0:
            1:
            2:
            3: