Why type casting doesn't work with String Type

Question

Please answer this
https://code.sololearn.com/c3cuW50Wncy1/?ref=app

Answer 1

Casting to String will work only if the object is a String:

Object text ="Hi there" ;
String str = (String) text ;

https://code.sololearn.com/c27ekjo2qtxY/?ref=app

converting int to string can be done this way :
"" + num;

Answer 2

// used types for casting must be compatible
// eg super class and sub class

public class Program {
public static void main(String[] args) {
System.out.println( (Number) 12345 ); //12345

CharSequence c = "12345";
System.out.println( (String) c ); //12345

B b = new B();
System.out.println( ( (A) b ).i); //12345
}
}
class A {
int i = 12345;
}
class B extends A {
int i = 22222;
}

Answer 3

zemiak Ah ok, I see what you were going for. Makes sense.

Answer 4

String b=String.valueOf(12345);
System.out.println(b.length());

Answer 5

What zemiak said, except dont use b.length() just use b, otherwise if you do String.valueOf(5) System.out.println(b.length()) it would output an int 1 and not a string 5