Illinois Criminal Code 720 ILCS 5/24-1.  Unlawful Use of Weapons.

(a) A person commits the offense of unlawful use of weapons when he knowingly... 

(2) Carries or possesses with intent to use the same unlawfully against another, a

   dagger, dirk, billy, dangerous knife, razor, stiletto, broken bottle or other piece of glass... or any other

   dangerous or deadly weapon of like character...

 720 ILCS 5/33A-1

... A person is considered armed with a dangerous weapon... when he carries on or about his person

   or is otherwise armed with a category I or category II weapon.

(b) A category I weapon is a [firearm or] a knife with a blade at least 3 inches in length, dagger, dirk,

   switchblade knife, stiletto, or any other deadly or dangerous weapon of like character.

720 ILCS 5/24-1. Unlawful Use of Weapons.

(a) A person commits the offense of unlawful use of weapons when he knowingly:

(1) Sells, manufactures, purchases, possesses or carries any... knife commonly referred to as a

   switchblade knife, which has a blade that opens automatically by hand pressure applied to a button, spring

   or other device in the handle of the knife, or a ballistic knife, which is a device that propels a knifelike blade as

   a projectile by means of a coil spring, elastic material, or compressed gas...