# 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|