catch(onRejected?: (reason?: any)): IPromise
Call the function after a promise is rejected.
The function which will be executed when a promise is rejected. This has a single parameter, the rejection reason. The return value will be passed to the next callback function.
then(onFulfilled?: (value?: any), onRejected?: (reason?: any)): IPromise
Call the function after a promise is fulfilled or rejected.
The function which will be executed when a promise is fulfilled. This has a single parameter, the fulfillment value. If a value is returned, it will be passed to the next callback function. If no value is returned, the original value will be passed.
The function which will be executed when a promise is rejected. This has a single parameter, the rejection reason. If a value is returned, it will be passed to the next callback function. If no value is returned, the original value will be passed.
Defines the interface of promise which is used for asynchronous calling.