However, in case you are young and undecided you can still have a short-term objective instead of a long-term one. Your short-term objective should be anything but monetary benefit (which though it is high on everyone's mind, looks very shallow on the CV). Hence, you could say that you want to gain experience in a particular field, or understand a particular industrial functioning and see the fit, etc.

Your objective should be a close match to the overall objective of the job you are applying for, hence, whenever you are applying for a job the objective should be slightly modified to exactly fit that particular job. Do not under any circumstance state that the objective is undecided. Such an answer will show complete immaturity and will definitely invite summary rejection.

The CV should always reflect that you are in control and I am sure you can understand how important the is objective to show that you are in control. Otherwise you will seem like a driver who is raring to go, but has no exact destination. The company would feel threatened to use such talent as there is no guarantee that they would be satisfied and/or that you would stick to the job for a long period (or at least a reasonable period of time).

It is best for those who have deep doubt of what exactly out of their professional life, not to mention it at all. There are CV formats which allow for this, but its absence from the CV may ensure that it would be asked during the interview for which you should be carefully prepared.

To summarize, state an objectives only when you have totally internalized it; state short-term objective when you do not have long-term objectives; customize each objective to fit exactly with each job you are applying for.