I have 2 arrays like so:

```
var arrayOne = [
    {page:'1',tags:['foo','bar']},
    {page:'2',tags:['oh','boy']}
];
var arrayTwo = [
    {page:'1',tags:['go','out']},
    {page:'9b',tags:['red','blue','green']}
];

```

I want to compare the two arrays, and if the `page` property is the same, replace the `tags` property in `arrayOne` with the `tags` property from `arrayTwo`.

So given the example arrays above, only the tags for `page: 1` of `arrayOne` would get replaced with `page: 1`'s values from `arrayTwo`.

I'm thinking I can do this with `underscore.js`, but I'm struggling to see how.

Ideas?