1# SensorService Kit Changelog
2
3## cl.sensors.1 Change of the count Attribute of VibratePreset from Mandatory to Optional
4
5**Access Level**
6
7Public API
8
9**Reason for Change**
10
11The **count** parameter of **VibratePreset** is mandatory even if the number of vibrations is **1**.
12
13**Change Impact**
14
15This change is a non-compatible change.
16
17Before change: The **count** attribute of **VibratePreset** is mandatory.
18
19```ts
20interface VibratePreset {
21    type: 'preset';
22    effectId: string;
23    count: number;
24}
25```
26
27After change: The **count** attribute of **VibratePreset** is optional, and the default value is **1**.
28
29```ts
30interface VibratePreset {
31    type: 'preset';
32    effectId: string;
33    count?: number;
34}
35```
36
37**Start API Level**
38
399
40
41**Change Since**
42
43OpenHarmony SDK 5.0.0.27
44
45**Key API/Component Changes**
46
47count of VibratePreset in @ohos.vibrator.d.ts.
48
49**Adaptation Guide**
50
51The **count** attribute of **VibratePreset** is optional. If your app has a dependency on the type of this attribute, adaptation is required. For example, if the type of **count** is a number before change, you need to set the type of **count** to **number | undefined** after change.
52
53```ts
54let effect: VibratePreset = {
55    type: 'preset',
56    effectId: 'xxx',
57    count: 2
58};
59
60let count: number | undefined = effect.count;
61```
62