?? Null Coalescing Operator --> What does coalescing mean?

Question

I\'m tempted to lie and say that English is my second language, but the truth is that I just have no idea what \'Coalescing\' means. I know what ?? \'does\' in

Answer 1

You can start from this youtube video http://www.youtube.com/watch?v=YJGGmTNHPeo

If you see the English meaning of coalescing it says “consolidate together”. Coalescing operator returns the first NON-NULL value from a chain.

For example below is a simple coalescing code which chains four strings.So if “str1” is null it will try “str2” , if “str2” is null it will try “str3” and so on until it finds a string with a non-null value.

string final =str1 ??  str2 ?? str3 ??