
352 A.2d 396 (1976)
John PERRY
v.
Eugene P. PETIT, Jr., Registrar.
No. 74-182-M. P.
Supreme Court of Rhode Island.
March 1, 1976.
Aram K. Berberian, Cranston, for petitioner.
Julius C. Michaelson, Atty. Gen., Forrest L. Avila, Special Asst. Atty. Gen., for respondent.

OPINION
PER CURIAM.
This is a petition for certiorari to review a judgment entered in the Superior Court sustaining the petitioner's appeal, on constitutional grounds, from a decision of the respondent Registrar of Motor Vehicles denying the petitioner's application for a motor vehicle operator's license and remanding the case to the registrar for a further hearing. On September 19, 1974, we granted the petition and ordered the writ to issue forthwith.
The case was heard before us on February 6, 1976. The petitioner's principal argument was that the Superior Court should have ordered the registrar to grant the operator's license to petitioner, instead of remanding the case to the registrar for a further hearing. During the hearing counsel informed us that in September 1975, while the cause was pending in this court, the registrar granted petitioner's application for an operator's license. The respondent suggested that in the circumstances the matter was moot. We agree.
This court will not ordinarily spend its time either proceeding to adjudicate when there is no subject matter on which its judgment can operate or in deciding a moot case. Kimball v. Pelosi, 96 R.I. 429, 192 A.2d 267 (1963). Nor will we review a case on certiorari or other prerogative writ if our mandate will be of no assistance to the party seeking our assistance because what he asks for has already been done. Lauder v. Zoning Board of Review, 100 R.T. 641, 218 A.2d 476 (1966). Since the registrar has already issued an operator's license to the petitioner without a court order, *397 the petitioner has received what he asked for and no further action is necessary.
The petition for certiorari is denied and dismissed, the writ heretofore issued is quashed, and the records certified are remanded to the Superior Court with our decision endorsed thereon.
