[JAVA]StringBuilder, .append(), .toString()

//StringBuilder class //java.lang.StringBuilder
//methods: .append() .toString()
//

import java.util.Scanner;
public class StrBuilder
{
    public static void main(String[] args)
    {
        Scanner userInput = new Scanner(System.in);

        StringBuilder builder = new StringBuilder();

        System.out.println(builder.getClass().getName()); //object中可以获取类名

        System.out.println("what's your name? ");
        String name = userInput.nextLine();
        builder.append("My name is " + name);
        System.out.println(builder);


        System.out.println("How old are you?");
        int age = userInput.nextInt();
        builder.append(". I'm " + age + " years old.");


        //System.out.println(builder.toString());
        System.out.println(builder);
    }
}