小编gau*_*dey的帖子

Code with val and var:

val adder: Int => Int = _ + 3 // Works fine
var adder: Int => Int = (_ + 3) // Works fine
var adder: Int => Int = _ + 3 // Error (using var, but not brackets)

Error message for the last line with var:

';' expected but identifier found.

What can explain the difference in behavior between the val and var variant?