Dynamic typing vs. type inference

compilation.txt

~/exp% /usr/lib/jvm/java-19/bin/javac Main.java
Main.java:13: error: cannot find symbol
        System.out.println(x.length());
                            ^
  symbol:   method length()
  location: variable x of type Object
1 error

Main.java

public class Main{

    private static Object getValue() {
        // We return String, but the type is just more generic Object
        return "hello world";
    }

    public static void main(String...args) {
        // javac sees that getValue() returns Object, so the type of x is also Object
        var x = getValue();
        // Although x contains a String, it is typed as Object, so we cannot call length() method.
        // When we change the getValue()'s return type to String, it changes x's type to String and this file compiles.
        // If we had a dynamic typing, we would be able to call length() anyway.
        System.out.println(x.length());
    }

}