In WW2, did the japanese have radar and Sonar ?

Yes they did. They developed it on their own. The basic principals were not a secret.

Radar was invented before World War II. There was an active radar installation on Oahu at Opana Point that actually tracked the inbound Japanese aerial armada. They were told it was USAAF B-17's that were scheduled to arrive that day.

The Japanese were shown German and British radar units during a visit to Germany in 1940. After Pearl Harbor, the Germans shipped one of their radars to Japan. There is no evidence that the Japanese fielded sonar in their vessels during World War II.

As early as 1886, German physicist Heinrich Hertz showed that radio waves could be reflected from solid objects. In 1895, Alexander Popov, a physics instructor at the Imperial Russian Navy school in Kronstadt, developed an apparatus using a coherer tube for detecting distant lightning strikes. The next year, he added a spark-gap transmitter. In 1897, while testing this equipment for communicating between two ships in the Baltic Sea, he took note of an interference beat caused by the passage of a third vessel. In his report, Popov wrote that this phenomenon might be used for detecting objects, but he did nothing more with this observation.[2]

The German inventor Christian Hülsmeyer was the first to use radio waves to detect "the presence of distant metallic objects". In 1904 he demonstrated the feasibility of detecting a ship in dense fog, but not its distance from the transmitter.[3] He obtained a patent[4] for his detection device in April 1904 and later a patent[5] for a related amendment for estimating the distance to the ship. He also got a British patent on September 23, 1904[6] for a full system, that he called a telemobiloscope.

In August 1917 Nikola Tesla outlined a concept for primitive radar-like units.[7] He stated,

...by their [standing electromagnetic waves] use we may produce at will, from a sending station, an electrical effect in any particular region of the globe; [with which] we may determine the relative position or course of a moving object, such as a vessel at sea, the distance traversed by the same, or its speed.

My Uncle Vernon installed radar on PT 59..JFK's 2nd PT Boat.

Now look up how they and microwave ovens work!

SSG US Army 73-82

Avionics and Signal

PS if you look into the Imperial Navy you would know they did some stuff long before others....in regards to Ohms Law and the Imperial Navy. Try the search line.

No. Japanese doctrine concerning submarines was that they should be used to track and destroy elements of the enemy surface fleet,so as to weaken its strength prior to any decisive naval fleet engagement,which would then help the Japanese fleet to win any such engagement. As a result,Japanese submarines spent most of WW2 in attempts to find and sink US capital ships.Given the advances in submarine detection technology and anti submarine warfare even before WW2,this strategy was largely unsuccessful,and led to the loss of many Japanese submarines with little return result in terms of destroyed US warships.It also meant that the US merchant marine was largely untroubled by Japanese submarine attacks in WW2,as these subs were busy trying to sink US warships rather than US merchant ships. It was the USA subs that followed a German style strategy of targetting the enemy merchant marine in WW2 - this crippled the Japanese merchant fleet and eventually cut supply lines between Japan and its forces in China and its garrisons on the islands in the path of the US island hopping campaign,and was a significant factor in US strategic success in the Pacific theatre.

the brits invented radar,was developed by the germans, then america.japan developed many technoligies.microwave generators,Once one country develops a tech everyone grabs hold.

Sonar Ww2

I need more details