# wire.Collection

A collection is a basic programming structure that allows an array of objects to be maintained using a field as a unique key.

The following creates a new `Collection` object from `users` using the `UserName` field as the key.  The first parameter to the constructor is the key field and the second is the array of objects.

```javascript
let users = [
    { UserName: "apeters", FullName: "Amy Peters" },
    { UserName: "pdougherty", FullName: "Pat Dougherty" },
    { UserName: "tleach", FullName: "Tim Leach" }
];

let collection = new wire.Collection("UserName", users);
```

Use the following methods to maintain a collection of users.

## Methods

| Name                     | Description                                                                                                                                                                                          |
| ------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| array                    | Returns the array of objects inside the collection.                                                                                                                                                  |
| clear                    | Clears the collections array.                                                                                                                                                                        |
| get(value)               | Returns the object with the key value `value`.                                                                                                                                                       |
| index(value)             | Returns the 0 index position of the object with the key value `value`.                                                                                                                               |
| length                   | Returns the length of the internal array.                                                                                                                                                            |
| move(fromIndex, toIndex) | Moves on object inside the collection from 0 index position `fromIndex` to `toIndex`.                                                                                                                |
| remove(key)              | Removes the object with the key value `value`.                                                                                                                                                       |
| set(object)              | Adds the object to the collection. If the object already exists with the existing key field value, it replaces the current one in the collection.  If not, it is added to the collection at the end. |

For more examples on using WireBootstrap collections, visit [Collections](https://docs.wirebootstrap.com/wirebootstrap/utilities/collections).