## TrendlineCollection class

Represents a collection of all the [Trendline](../trendline/) objects for the specified data series.

```javascript
class TrendlineCollection;
```


### Example
```javascript
const { Workbook, ChartType, TrendlineType, Color } = AsposeCells;

var excel = new Workbook();
var chartIndex = excel.worksheets.get(0).charts.add(ChartType.Column, 3, 3, 15, 10);
var chart = excel.worksheets.get(0).charts.get(chartIndex);
chart.nSeries.add("A1:a3", true);
chart.nSeries.get(0).trendLines.add(TrendlineType.Linear, "MyTrendLine");
var line = chart.nSeries.get(0).trendLines.get(0);
line.displayEquation = true;
line.displayRSquared = true;
line.color = Color.Red;
```
## Methods

| Method | Description |
| --- | --- |
| [get(number)](#get-number-)| Gets a [Trendline](../trendline/) object by its index. |
| [add(TrendlineType)](#add-trendlinetype-)| Adds a [Trendline](../trendline/) object to this collection with the specified type. |
| [add(TrendlineType, string)](#add-trendlinetype-string-)| Adds a [Trendline](../trendline/) object to this collection with specified type and name. |


### get(number) {#get-number-}

Gets a [Trendline](../trendline/) object by its index.

```javascript
get(index: number) : Trendline;
```

**Parameters:**
| Parameter | Type | Description |
| --- | --- | --- |
| index | number |  |

**Returns**

[Trendline](../trendline/)

### add(TrendlineType) {#add-trendlinetype-}

Adds a [Trendline](../trendline/) object to this collection with the specified type.

```javascript
add(type: TrendlineType) : number;
```

**Parameters:**
| Parameter | Type | Description |
| --- | --- | --- |
| type | [TrendlineType](../trendlinetype/) | Trendline type. |

**Returns**

[Trendline](../trendline/) object index.

### add(TrendlineType, string) {#add-trendlinetype-string-}

Adds a [Trendline](../trendline/) object to this collection with specified type and name.

```javascript
add(type: TrendlineType, name: string) : number;
```

**Parameters:**
| Parameter | Type | Description |
| --- | --- | --- |
| type | [TrendlineType](../trendlinetype/) | Trendline type. |
| name | string | Trendline name. |

**Returns**

[Trendline](../trendline/) object index.