## BookmarksOutlineLevelCollection class

A collection of individual bookmarks outline level.
To learn more, visit the [Working with Bookmarks](https://docs.aspose.com/words/nodejs-net/working-with-bookmarks/) documentation article.




### Remarks

Key is a case-insensitive string bookmark name. Value is a int bookmark outline level.

Bookmark outline level may be a value from 0 to 9. Specify 0 and Word bookmark will not be displayed in the document outline.
Specify 1 and Word bookmark will be displayed in the document outline at level 1; 2 for level 2 and so on.




### Constructors
| Name | Description |
| --- | --- |
| [BookmarksOutlineLevelCollection()](./constructor/#default) | The default constructor. |

### Properties

| Name | Description |
| --- | --- |
| [count](./count/) | Gets the number of elements contained in the collection. |
| [this[]](./this[]/) |  |
| [this[]](./this[]/) |  |

### Methods

| Name | Description |
| --- | --- |
|[ add(name, outlineLevel)](./add/#string_number) | Adds a bookmark to the collection. |
|[ clear()](./clear/#default) | Removes all elements from the collection. |
|[ contains(name)](./contains/#string) | Determines whether the collection contains a bookmark with the given name. |
|[ indexOfKey(name)](./indexOfKey/#string) | Returns the zero-based index of the specified bookmark in the collection. |
|[ remove(name)](./remove/#string) | Removes a bookmark with the specified name from the collection. |
|[ removeAt(index)](./removeAt/#number) | Removes a bookmark at the specified index. |

### Examples

Shows how to set outline levels for bookmarks.

```js
let doc = new aw.Document();
let builder = new aw.DocumentBuilder(doc);

// Insert a bookmark with another bookmark nested inside it.
builder.startBookmark("Bookmark 1");
builder.writeln("Text inside Bookmark 1.");

builder.startBookmark("Bookmark 2");
builder.writeln("Text inside Bookmark 1 and 2.");
builder.endBookmark("Bookmark 2");

builder.writeln("Text inside Bookmark 1.");
builder.endBookmark("Bookmark 1");

// Insert another bookmark.
builder.startBookmark("Bookmark 3");
builder.writeln("Text inside Bookmark 3.");
builder.endBookmark("Bookmark 3");

// When saving to .pdf, bookmarks can be accessed via a drop-down menu and used as anchors by most readers.
// Bookmarks can also have numeric values for outline levels,
// enabling lower level outline entries to hide higher-level child entries when collapsed in the reader.
let pdfSaveOptions = new aw.Saving.PdfSaveOptions();
let outlineLevels = pdfSaveOptions.outlineOptions.bookmarksOutlineLevels;

outlineLevels.add("Bookmark 1", 1);
outlineLevels.add("Bookmark 2", 2);
outlineLevels.add("Bookmark 3", 3);

expect(outlineLevels.count).toEqual(3);
expect(outlineLevels.contains("Bookmark 1")).toEqual(true);
expect(outlineLevels.at(0)).toEqual(1);
expect(outlineLevels.at("Bookmark 2")).toEqual(2);
expect(outlineLevels.indexOfKey("Bookmark 3")).toEqual(2);

// We can remove two elements so that only the outline level designation for "Bookmark 1" is left.
outlineLevels.removeAt(2);
outlineLevels.remove("Bookmark 2");

// There are nine outline levels. Their numbering will be optimized during the save operation.
// In this case, levels "5" and "9" will become "2" and "3".
outlineLevels.add("Bookmark 2", 5);
outlineLevels.add("Bookmark 3", 9);

doc.save(base.artifactsDir + "BookmarksOutlineLevelCollection.BookmarkLevels.pdf", pdfSaveOptions);

// Emptying this collection will preserve the bookmarks and put them all on the same outline level.
outlineLevels.clear();
```

### See Also

* module [Aspose.Words.Saving](../)