Understanding Promise (1)

You need to pass a new Promise actuator (function) function takes two parameters resolve reject

The default state is committed to promise to call pengding resolve for success reject indicate failure

Each has an instance method then promise

We can wait for the state => state success / failure status but not from the success / failure state to a failure / success

 

 

P = the let new new Promise (function (Resolve, Reject) { 
the console.log ( ' starts running ' ); 
Resolve ( ' Valentine to ' ); 
Reject ( ' To ' ); 
}) 
p.then ((value) = > { 
the console.log ( ' Success ' , value) 
}, (reason) => { 
the console.log ( ' erroe ' , reason) 
}); 
the console.log ( ' end of run ' )

run:

[Running] node "d:\码云\zhufengjiagoukecheng\promise\promise-apply.js"

To start running

End of run

Valentine's Day to success

[Done] exited with code=0 in 0.388 seconds

 

Although we know that we can call reject instantiated Promise in ( 'to'); but it does not print out from here, we know that when we => Success Success from waiting => failed the state does not perform