Assign value to variable only if is not null - Kotlin

Question

Is there a clean way in Kotlin to assign a value to a variable only if the value is not null?

My example is:

if(x != null)    y = x 

I found a solution like

y = x? : return 

but I don't understand if this does what I want and how this operator works.

Answer 1

Another solution if You don't want to return from function just yet:

x?.let{ y = it } 

Which checks if x is non-null then passes it as the only parameter to the lambda block.

This is also a safe call in case your x is a var.