Copy Files if getops is true

#!/bin/bash

folder="files"
[ -a "$folder" ] && echo "$folder exists" || mkdir "$folder"

move(){
  echo "Moving $1 for ${folder}..."
  mv $1  "$folder"
}

copy(){
  echo "Copying $1 for ${folder}..."
  cp $1 "$folder"
}

while getopts ":f:" arg; do
  case "$arg" in
    f)
      f="${OPTARG}"
      ;;
  esac
done

for file in *
do
  if [ "$f" = "true" ]
  then
    move "$file"
  else
    copy "$file"
  fi
done