# AbilityConstant
> ![icon-note.gif](public_sys-resources/icon-note.gif) **NOTE**
> The initial APIs of this module are supported since API version 9.
Provides parameters related to ability launch.
## Modules to Import
```js
import AbilityConstant from '@ohos.application.AbilityConstant';
```
## Attributes
| Name| Type| Readable| Writable| Description|
| -------- | -------- | -------- | -------- | -------- |
| launchReason | LaunchReason| Yes| Yes| Ability launch reason.
**System capability**: SystemCapability.Ability.AbilityRuntime.Core|
| lastExitReason | LastExitReason | Yes| Yes| Reason for the last exit.
**System capability**: SystemCapability.Ability.AbilityRuntime.Core|
## AbilityConstant.LaunchReason
Enumerates ability launch reasons.
| Name | Value | Description |
| ----------------------------- | ---- | ------------------------------------------------------------ |
| UNKNOWN | 0 | Unknown reason.
**System capability**: SystemCapability.Ability.AbilityRuntime.Core|
| START_ABILITY | 1 | Ability startup.
**System capability**: SystemCapability.Ability.AbilityRuntime.Core|
| CALL | 2 | Call.
**System capability**: SystemCapability.Ability.AbilityRuntime.Core|
| CONTINUATION | 3 | Ability continuation.
**System capability**: SystemCapability.Ability.AbilityRuntime.Core|
## AbilityConstant.LaunchReason
Enumerates reasons for the last exit.
| Name | Value | Description |
| ----------------------------- | ---- | ------------------------------------------------------------ |
| UNKNOWN | 0 | Unknown reason.
**System capability**: SystemCapability.Ability.AbilityRuntime.Core|
| ABILITY_NOT_RESPONDING | 1 | The ability does not respond.
**System capability**: SystemCapability.Ability.AbilityRuntime.Core|
| NORMAL | 2 | Normal status.
**System capability**: SystemCapability.Ability.AbilityRuntime.Core|
## AbilityConstant.OnContinueResult
Enumerates ability continuation results.
| Name | Value | Description |
| ----------------------------- | ---- | ------------------------------------------------------------ |
| AGREE | 0 | Continuation agreed.
**System capability**: SystemCapability.Ability.AbilityRuntime.Core|
| REJECT | 1 | Continuation denied.
**System capability**: SystemCapability.Ability.AbilityRuntime.Core|
| MISMATCH | 2 | Mismatch.
**System capability**: SystemCapability.Ability.AbilityRuntime.Core|