Longest word in List

Question

I have a List with Strings and I want to print the longest String out of it

I have tried the reduceLeft option but whenever I am applying it its returning this error:

type mismatch; found:String required:Ordering[?]

Here is the code throwing the exception in the second line:

val input2 = List("one", "two", "three", "four", "five")
for (entry <- input2.reduceLeft(_ max _)) println(input2.max)

Answer 1

you should ask yourself: What is the max for a list of Strings? List[String].max and String.max need more clarification for their task.

1. use List.maxBy instead of List.reduceLeft

   input2.maxBy(_.length)
   

2. use implicit type conversion

   implicit def string2ordering(s: String) = s.length
   input2.max