There isn't spot fat reduction if you do ab workouts.
Specific core exercise will in fact increase your functional strength. It will also help your posture. But it is important to note that if you were to do captain arm chairs or crunches, that you are not losing fat specifically in your stomach, however, you are losing calories and fat all over your body.
Spot reduction of body fat is very hard to prove, and it is often been tagged as a fallacy. But that doesn't mean you don't target your abs. You should if you wish to get stronger abs.