Question

I want to convert a char to an int value.
I am a bit puzzled by the way toInt works.

println(("123").toList)         //List(1, 2, 3)
("123").toList.head             // res0: Char = 1
("123").toList.head.toInt       // res1: Int = 49 WTF??????

49 pops up randomly for no reason.
How do you convert a char to int the right way?

Answer 1

Use Integer.parseInt(“1”, 10). Note that the 10 here is the radix.

val x = "1234"
val y = x.slice(0,1)
val z = Integer.parseInt(y)
val z2 = y.toInt //equivalent to the line above, see @Rogach answer
val z3 = Integer.parseInt(y, 8) //This would give you the representation in base 8 (radix of 8)

49 does not pop up randomly. It’s the ascii representation of “1”. See http://www.asciitable.com/