There is also a special null type, the type of the expression null, which has no name. Because the null type has no name, it is impossible to declare a variable of the null type or to cast to the null type. The null reference is the only possible value of an expression of null type.
The military barbell press mainly works the shoulder, or deltoid, muscles. The anterior deltoid, the front head of the shoulder muscle, does much of the work. The side, or lateral, deltoid and the rear, or posterior, deltoid are also involved in the movement, although to a lesser degree than the anterior deltoid.
1 The bench press or dumbbell bench-press is performed while lying face up on a bench, by pushing a weight away from the chest. 2  This is a compound exercise that also involves the triceps and the front deltoids, also recruits the upper and lower back muscles, and traps.