I have a JSON `var`

```
{
"total":4,
"page":1,
"pagesize":30,
"type":"associated_user",
"items":[
{
"user_id":2727,
"site_name":"Physics",
"user_creation_date":1300894372,
"association_id":"2fbcabe5-cd42-4f5b-821e-2f1475e42ade"
},
{
"user_id":3864,
"site_name":"TeX - LaTeX",
"user_creation_date":1298808016,
"association_id":"2fbcabe5-cd42-4f5b-821e-2f1475e42ade"
},
{
"user_id":5983,
"site_name":"Stack Apps",
"user_creation_date":1301323608,
"association_id":"2fbcabe5-cd42-4f5b-821e-2f1475e42ade"
},
{
"user_id":6260,
"site_name":"English Language and Usage",
"user_creation_date":1300449905,
"association_id":"2fbcabe5-cd42-4f5b-821e-2f1475e42ade"
}
]
}

```

As you can see, there are four `site_name` keys in `items` block. I can access only the first using `items[0].site_name` but how to access the other three one by one?