What's the difference between using and no using a “=” in Scala defs ?

Question

What the difference between the two defs below

def someFun(x:String) { x.length } 

AND

def someFun(x:String) = {          


        

Answer 1

The former is

def someFun(x: String): Unit = {
  x.length
  ()  // return unit
}

And the latter is

def someFun(x: String): Int = {
  x.length  // returned
}