This command will create a basic prismatic joint between the specified bodies. This type of joint will only allow the child body to move along one specified line. The BodyID1 and BodyID2 specify the bodies involved and should be the integer handles of those bodies. The X and Y, aX and aY values define a line that specifies the imaginary line the second body will move along - the bodies should already be positioned so they are at the proper angle.
Image Source: Box2D User Manual
SyntaxReturn as Integer = b2CreatePrismaticJoint(ID as Integer,
Body1ID as Integer, Body2ID as Integer, X as Float, Y as
Float, aX as Float, aY as
Float)