Count all occurrences of a char within a string

Question

Does Scala have a native way to count all occurrences of a character in a string?

If so, how do I do it?

If not, do I need to use Java? If so, how do I do

Answer 1

You can also take a higher level approach to look into substring occurrences within another string, by using sliding:

def countSubstring(str: String, sub: String): Int =
  str.sliding(sub.length).count(_ == sub)