С материала който е взет и до сега ,можеш да я решиш : решението ми е на java ,но ше го разбереш.

public class DataType2 {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        String input=scan.nextLine();
        while (!input.equals("END")){
            boolean isInt=false; boolean isDouble=false;int count=0; int dot=0;
            for(int i=0;i<input.length(); i++){
                char n=input.charAt(i);
                if(n>47&&n<58) {
                    count++;
                }else if(n==46){
                    dot++;
                }else if(i==0&&n==45){
                    count++;
                }
                if(count==input.length()){
                    isInt=true;
                }else if((count+1==input.length())&& dot==1){
                        isDouble=true;
                    }
            }
            if (isInt) {
                System.out.printf("%s is integer type%n", input);
            } else if (isDouble) {
                System.out.printf("%s is floating point type%n", input);
            } else if (input.length() == 1) {
                System.out.printf("%s is character type%n", input);
            } else if ("true".equals(input.toLowerCase()) || "false".equals(input.toLowerCase())) {
                System.out.printf("%s is boolean type%n", input);
            } else {
                System.out.printf("%s is string type%n", input);
            }
            input=scan.nextLine();
        }
    }
}