Express Revocation:
If a testator makes a bequest of some property to a person, and by subsequent will, he bequeaths the same property to another person, the first bequest is revoked. But bequest of the same property to one person in earlier portion of the will and to another person in the later portion of the will does not revoke the earlier bequest, but both the Jegatees share the property equally. A will may be expressly revoked by fearing it off, or by burning it. It seems that mere denial of a will will not operate as its revocation.
Implied Revocation:
Any act inconsistent with the bequest will go to revoke the will. Thus, an act which results in the extinction of the subject-matter of the bequest, or extinction of the proprietary rights of the testator will impliedly revoke the will. For instance, bequest of a plot of land is revoked when the testator builds a house on it; or bequest of a house is revoked when the testator sells or makes a gift of it to another.
