Well in the US the increase in production helped the economy significantly, pulling the US out of the depression. I do not know if WWII significantly boosted Europe's economy.

As for other wars, no wars were quite like WWII. Take WWI, the world wasn't in a depression when the war started, but the utter devastation the war brought to Europe, and the terms of the Treaty of Versailles, brought Germany to ruins, giving an example of a war that damaged the economy.

The Korean War was a boom for Australia since we could churn out wool for the war effort and the ending of it hurt us economically. Im not sure about the Vietnam was but i think it had the same effect.

War is basically spending a ton of money to equip men and women to go fight something. That money is used to buy equipment and items and those that can supply said items get an economic boost. So all wars should improve the economy but if said economy is doing poorly or already strong then the improvement might be marginal or greatly exaggerated i.e. WW2 is often said to have dragged the US out of the Depression due to the massive expenditure, hiring of workers to supply the war etc which contrasted with the economic situation before the war i.e. the depression.

For the US, since we didn't turn our economy into a pure war economy, we had consumer goods to fall back on once the war ended. In addition, industries that were heavily involved in war production,like the auto industry, were able to revert back to consumer products within months. Other countries could not have such quick turn around or their industry was destroyed as a result of the war.

In addition, the pent up consumer demand, back by significant savings, was able to drive the US and British economies through the 1970's until the first oil embargo.

Countries that destroyed because if the war, mainly Germany and Japan, were able to have a clean start. They could, through proper planning and resourcing (and significant investment through the Marshall Plan), invest in newer technologies and manufacturing procedures that allowed them to directly compete with the US and UK starting in the 1960's.

For the majority of the West (including Japan), WW2 proved to be a generally positive event in terms of economics. some benefited directly, but most indirectly.

For an American perspective, read

Freedoms forge: how american business produced victory in world war 2