How can I check if an input is a integer or String, etc.. in JAVA?

Question

I am wondering how I can check if a user\'s input is a certain primitive type (I mean integer, String, etc... I think it\'s called primitive type?). I want a user to input s

Answer 1

But Zechariax wanted an answer with out using try catch

You can achieve this using NumberForamtter and ParsePosition. Check out this solution

import java.text.NumberFormat;
import java.text.ParsePosition;


    public class TypeChecker {
        public static void main(String[] args) {
        String temp = "a"; // "1"
        NumberFormat numberFormatter = NumberFormat.getInstance();
        ParsePosition parsePosition = new ParsePosition(0);
        numberFormatter.parse(temp, parsePosition);
        if(temp.length() == parsePosition.getIndex()) {
            System.out.println("It is a number");
        } else {
            System.out.println("It is a not number");
        }
    }
}

Answer 2

Use instanceof to check type and typecast according to your type:

 public class A {

    public static void main(String[]s){

        show(5);
        show("hello");
    }
    public static void show(Object obj){
        if(obj instanceof Integer){
            System.out.println((Integer)obj);
        }else if(obj instanceof String){
            System.out.println((String)obj);
        }
    }
}