The term "firearm" is defined in N.J.S.A. 2C:39-1f. It provides: "Firearm" means any handgun, rifle, shotgun, machine gun, automatic or semiautomatic rifle, or any gun, device or instrument in the nature of a weapon from which may be fired or ejected any solid projectable ball, slug, pellet, missile or bullet, or any gas, vapor or other noxious thing, by means of a cartridge or shell or by the action of an explosive or the igniting of flammable or explosive substances. It shall also include, without limitation, any firearm which is in the nature of an air gun, spring gun or pistol or other weapon of a similar nature in which the propelling force is a spring, elastic band, carbon dioxide, compressed or other gas or vapor, air or compressed air, or is ignited by compressed air, and ejecting a bullet or missile smaller than three-eighths of an inch in diameter, with sufficient force to injure a person. N.J.S.A. 2C:39-1f. In State v. Butler, 89 N.J. 220, 229, 445 A.2d 399 (1982) the defendant pretended to have a gun in committing a robbery, but was unarmed. The Court held that, as "deadly weapon" was then defined in N.J.S.A. 2C:11-1(c), there could be no armed robbery based on a victim's mere perception that the assailant had a weapon. Butler, supra, 89 N.J. at 229, 445 A.2d 399. Indeed, the Court found the "objective presence of a deadly weapon" was needed to give rise to an armed robbery. Id. at 230, 445 A.2d 399. However, the Court did not hold that a firearm was not a "deadly weapon."