<Regex doesn't change string> I want to remove all...

# stackoverflow

[user]

Regex doesn't change string
I want to remove all symbols that aren't letters or numbers, but my string isn't changed.
fun main() {
var testStr = "Hello, World 2022!"
countWords(testStr)
}

fun countWords(input: String) {

val regex ="""^A-Za-z0-9""".toRegex()
val inputChanged = input.replace(regex, " ")
println("changed input: $inputChanged")

}