Un-lawful consideration and object

Un-lawful consideration:
According to sec. 10 of the contract act.
“An agreement is a contract enforceable only if it is made for a lawful consideration and which a lawful object.”

Causes of unlawful consideration:
According to sec 23. The consideration or object of an agreement is unlawful in the following cases.
(I) Prohibited by law:
If the object of a agreement is prohibited by law agreement will be void.
(II) Element of fraud:
If there is element of fraud in the object of agreement, the consideration will be unlawful.
(III) Immoral:
If case of immoral, the consideration will be unlawful.
(Iv) against public policy:
If the object of consideration of an agreement as opposed to public policy, the consideration will be unlawful.
(v) Injury to other person or property:
If the object or consideration of agreement is to cause an injury to the person or property of another is illegal and void.