Every person appointed county prosecutor shall, before entering upon the duties of his office, take and subscribe before the clerk of the county for which he has been appointed, or before a judge of the Superior Court, the following oath:
"I, .................. , do solemnly promise and swear (or affirm), that I will faithfully, justly and impartially execute the duties of county prosecutor of this State, in and for the county of .................... , to the best of my abilities and understanding. So help me God."