A more thorough explanation:

A constructive contract, also known as a quasi-contract, is a legal obligation that is created by the law of equity and justice when there is no agreement between the parties. This is done to prevent unjust enrichment. It is important to note that a court cannot find a quasi-contract if there is already an existing contract, either express or implied, covering the same subject matter.

For example, if a person hires a contractor to build a house, and the contractor does not complete the work, the homeowner may be able to recover the cost of the work that was not completed. This is because the homeowner conferred a benefit upon the contractor, and it would be unfair for the contractor to keep the money without completing the work.

Another example of a constructive contract is when a person finds a lost item and returns it to the owner. The person who found the item may be entitled to a reward or compensation for their efforts. This is because the owner of the lost item received a benefit from the person who found it, and it would be unfair for the owner to keep the item without compensating the person who found it.

In both examples, a benefit was conferred upon one party, and it would be unfair for that party to keep the benefit without compensating the other party. This is where a constructive contract comes into play, as it creates a legal obligation to prevent unjust enrichment.