[near-runtime-ts](../README.md) > ["collections/persistentVector"](../modules/_collections_persistentvector_.md) > [PersistentVector](../classes/_collections_persistentvector_.persistentvector.md)

# Class: PersistentVector

A vector class that implements a persistent array.

## Type parameters
#### T 
## Hierarchy

**PersistentVector**

## Indexable

\[key: `number`\]: `T`
A vector class that implements a persistent array.

## Index

### Constructors

* [constructor](_collections_persistentvector_.persistentvector.md#constructor)

### Accessors

* [back](_collections_persistentvector_.persistentvector.md#back)
* [first](_collections_persistentvector_.persistentvector.md#first)
* [front](_collections_persistentvector_.persistentvector.md#front)
* [isEmpty](_collections_persistentvector_.persistentvector.md#isempty)
* [last](_collections_persistentvector_.persistentvector.md#last)
* [length](_collections_persistentvector_.persistentvector.md#length)

### Methods

* [containsIndex](_collections_persistentvector_.persistentvector.md#containsindex)
* [pop](_collections_persistentvector_.persistentvector.md#pop)
* [popBack](_collections_persistentvector_.persistentvector.md#popback)
* [push](_collections_persistentvector_.persistentvector.md#push)
* [pushBack](_collections_persistentvector_.persistentvector.md#pushback)

---

## Constructors

<a id="constructor"></a>

###  constructor

⊕ **new PersistentVector**(prefix: *`string`*): [PersistentVector](_collections_persistentvector_.persistentvector.md)

*Defined in [collections/persistentVector.ts:12](https://github.com/nearprotocol/near-runtime-ts/blob/6995971/assembly/collections/persistentVector.ts#L12)*

Creates or restores a persistent vector with a given storage prefix. Always use a unique storage prefix for different collections.

**Parameters:**

| Name | Type | Description |
| ------ | ------ | ------ |
| prefix | `string` |  A prefix to use for every key of this vector. |

**Returns:** [PersistentVector](_collections_persistentvector_.persistentvector.md)

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## Accessors

<a id="back"></a>

###  back

**get back**(): `T`

*Defined in [collections/persistentVector.ts:160](https://github.com/nearprotocol/near-runtime-ts/blob/6995971/assembly/collections/persistentVector.ts#L160)*

**Returns:** `T`
The last element of the vector. Asserts that the vector is not empty.

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<a id="first"></a>

###  first

**get first**(): `T`

*Defined in [collections/persistentVector.ts:183](https://github.com/nearprotocol/near-runtime-ts/blob/6995971/assembly/collections/persistentVector.ts#L183)*

**Returns:** `T`
The first element of the vector. Asserts that the vector is not empty.

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<a id="front"></a>

###  front

**get front**(): `T`

*Defined in [collections/persistentVector.ts:175](https://github.com/nearprotocol/near-runtime-ts/blob/6995971/assembly/collections/persistentVector.ts#L175)*

**Returns:** `T`
The first element of the vector. Asserts that the vector is not empty.

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<a id="isempty"></a>

###  isEmpty

**get isEmpty**(): `bool`

*Defined in [collections/persistentVector.ts:44](https://github.com/nearprotocol/near-runtime-ts/blob/6995971/assembly/collections/persistentVector.ts#L44)*

**Returns:** `bool`
True if the vector is empty.

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<a id="last"></a>

###  last

**get last**(): `T`

*Defined in [collections/persistentVector.ts:168](https://github.com/nearprotocol/near-runtime-ts/blob/6995971/assembly/collections/persistentVector.ts#L168)*

**Returns:** `T`
The last element of the vector. Asserts that the vector is not empty.

___
<a id="length"></a>

###  length

**get length**(): `i32`

*Defined in [collections/persistentVector.ts:51](https://github.com/nearprotocol/near-runtime-ts/blob/6995971/assembly/collections/persistentVector.ts#L51)*

**Returns:** `i32`
The length of the vector.

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## Methods

<a id="containsindex"></a>

###  containsIndex

▸ **containsIndex**(index: *`i32`*): `bool`

*Defined in [collections/persistentVector.ts:37](https://github.com/nearprotocol/near-runtime-ts/blob/6995971/assembly/collections/persistentVector.ts#L37)*

**Parameters:**

| Name | Type | Description |
| ------ | ------ | ------ |
| index | `i32` |  The index to check. |

**Returns:** `bool`
True if the given index is within the range of the vector indices.

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<a id="pop"></a>

###  pop

▸ **pop**(): `T`

*Defined in [collections/persistentVector.ts:138](https://github.com/nearprotocol/near-runtime-ts/blob/6995971/assembly/collections/persistentVector.ts#L138)*

Removes the last element from the vector and returns it. Asserts that the vector is not empty. Decreases the length of the vector.

**Returns:** `T`
The removed last element of the vector.

___
<a id="popback"></a>

###  popBack

▸ **popBack**(): `T`

*Defined in [collections/persistentVector.ts:153](https://github.com/nearprotocol/near-runtime-ts/blob/6995971/assembly/collections/persistentVector.ts#L153)*

Removes the last element from the vector and returns it. Asserts that the vector is not empty. Decreases the length of the vector.

**Returns:** `T`
The removed last element of the vector.

___
<a id="push"></a>

###  push

▸ **push**(element: *`T`*): `i32`

*Defined in [collections/persistentVector.ts:116](https://github.com/nearprotocol/near-runtime-ts/blob/6995971/assembly/collections/persistentVector.ts#L116)*

Adds a new element to the end of the vector. Increases the length of the vector.

**Parameters:**

| Name | Type | Description |
| ------ | ------ | ------ |
| element | `T` |  A new element to add. |

**Returns:** `i32`
The index of a newly added element

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<a id="pushback"></a>

###  pushBack

▸ **pushBack**(element: *`T`*): `i32`

*Defined in [collections/persistentVector.ts:129](https://github.com/nearprotocol/near-runtime-ts/blob/6995971/assembly/collections/persistentVector.ts#L129)*

Adds a new element to the end of the vector. Increases the length of the vector.

**Parameters:**

| Name | Type | Description |
| ------ | ------ | ------ |
| element | `T` |  A new element to add. |

**Returns:** `i32`
The index of a newly added element

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