States of a promise

Promise is based on three states. Each state has a significance and can be used to drive a certain level of result as per the need. This can help a programmer choose as per his/her need. The three states of a promise are as follows:

• Pending: This is the initial state of a promise
• Fulfilled: This is the state of a promise representing a successful operation
• Rejected: This is the state of a promise representing a failed operation

Once a promise is fulfilled or rejected, it is immutable (that is, it can never change again).

With reference to the concepts discussed earlier, it's now clear what a promise is and how you can use it with all its potential.