public class DemoApp {
    public static void main(String[] args) {
        System.out.println("start");
        String val = "original";
        try {
            val = caller();  // remains "original"
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        System.out.println(val); // "original"
    }

    public static String caller() throws Exception {
        int x = 100;
        int y = 0;
        try {
            System.out.print("before ");
            int z = x / y;
            return "success";  // skipped
        } catch (Exception e) {
            System.out.print("caught ");
            throw new Exception("failure");
        }
    }
}

• The throw inside catch terminates the method immediately; no further statements in that method execute. Omitting the final return is valid because the exception already exits the method.
• The division by zero occurs at int z = x / y;. Code before this line runs normally, but the subseqeunt return is never reached. Flow jumps straight into the catch block.
• In main, val = caller() never completes the assignment because caller() throws an exception. The variable val keeps its previous value "original".

public class DemoApp {
    public static void main(String[] args) {
        System.out.println("start");
        String val = "original";
        try {
            val = handler(); // becomes "fallback"
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        System.out.println(val); // "fallback"
    }

    public static String handler() throws Exception {
        int x = 100;
        int y = 0;
        try {
            System.out.print("before ");
            int z = x / y;
            return "success";  // skipped
        } catch (Exception e) {
            System.out.print("captured ");
        }
        return "fallback";
    }
}

• If the catch block does not rethrow or return, the method continues to the default return statement. The method must provide a return value on all paths; removing the final return causes a compilation error.
• Here handler() completes successfully and returns "fallback". The variable val in main updates to "fallback".
• Since handler() no longer throws an exception, the caller does not need a try-catch and can be simplified:

public class DemoApp {
    public static void main(String[] args) {
        System.out.println("start");
        String val = "original";
        val = handler();         // "fallback"
        System.out.println(val); // "fallback"
    }

    public static String handler() {
        int x = 100;
        int y = 0;
        try {
            System.out.print("before ");
            int z = x / y;
            return "success";
        } catch (Exception e) {
            System.out.print("captured ");
        }
        return "fallback";
    }
}