Question

I have a collection of objects objcol1(example Collection of cities in a state) and another object collection objcol2(example collection of cities in a country). Now I am querying for objcol1 and I want to add it to objcol2. I can do this by iterating through objcol1 and adding one by one to objcol2 but can I directly add objcol1 to objcol2 like
objcol2.add(objcol1);

Can anyone tell me whether it is possible without iterating? If yes please explain me the process

Answer 1

You could use the Enumerable.Concat extension method:

objcol1 = objcol1.Concat(objcol2)

I’m sure under the covers somewhere it actually iterates, but you won’t need to write the code to do it.

NOTE: This will only work if your City objects are the same, alternatively you could use Select to map the objects.