Final answer:
Promissory estoppel is a legal doctrine that allows a party to enforce a promise, even without a formal contract. The cause of action for promissory estoppel requires a clear promise, reliance, detrimental reliance, and injustice if the promise is not enforced.
Step-by-step explanation:
Promissory estoppel is a legal doctrine that allows a party to enforce a promise, even if there is no formal contract between the parties. It is a doctrine that prevents one party from denying a promise made to another party if the other party relied on that promise to their detriment.
The cause of action for promissory estoppel arises when four elements are met: a clear and definite promise, reliance on the promise by the party to whom it was made, foreseeable and detrimental reliance, and injustice if the promise is not enforced.
For example, suppose you applied for a job and received a letter stating that you have been hired, but the employer later changes their mind and refuses to hire you. In this case, you may have a cause of action for promissory estoppel because you relied on the promise of employment to your detriment.