JavaScript traverses object's property values

Data parsing encountered a small problem, JSON format data multi-layer nesting, probably long so, in fact, the structure is more complex than this
Ex

{"
data": [
    {
        "criminal": [4,0,0,0,0,0,0,0,0,0,0,0],
        "Fire": [0,0,0,0,0,0,0,0,0,0,0,0],
        "Law and Order": [ 2,0,0,0,0,0,0,0,0,0,0,0],
        "Traffic": [3,0,0,0,0,0,0,0,0,0,0,0],
        "help": [2,0,0,0,0,0,0,0,0,0,0,0],
        "other": [ 0,0,0,0,0,0,0,0,0,0,0,0]
    },
    {
      "time": { 
      "date": +,
      "Day": 5,
      "hours":
      " Minutes ":", "
      month": One,
      "seconds": "," Time
      ": 1513925906648,
      " Timezoneoffset ": -480,
      " Year ': 117
      }
  }
  ]
}

Want to traverse to get the array in the object:
In JavaScript, an array can be iterated, but the object is initially traversed with a for loop, showing the undefined;
Such as:

for (Var Key in res.data.data[0]) {
    console.log (key+ ': ' +res.data.data[0]. Key);
}

And the following can be:

   for (Var Key in res.data.data[0]) {
    console.log (key+ ': ' +res.data.data[0][key]);
   }

Another example:

var data ={
      ' Cloudy Day ': ', '
      Sunny ': ' Bayi ',
      ' rainy Day ': ' A '
};
So: for
(var Key in data) {
     Console.log (key+ ': ' +data[key]);
}

The above can be printed on the console:
Cloudy Day: 15
Sunny days: 81
Rainy Days: 12

and the following is not

for (var y in data) {
      Console.log (y+ ': ' +data[y]);
}

Will print on the console:
Cloudy Day: Undefined
Sunny Day: undefined
Rainy Day: undefined