I am trying to learn java, and I’m in the wrapper classes topic. I am trying to use Boolean, Character, Integer and Double wrapper classes and assign value to them treating them as primitive data types. The tutorial I am watching is not having this error but I did.

Error: Exception in thread “main” java.lang.Error: Unresolved compilation problems:
Type mismatch: cannot convert from boolean to Boolean
Type mismatch: cannot convert from int to Integer
Type mismatch: cannot convert from double to Double

at MyPackage.Main.main(Main.java:19)

Here is the code:

            Boolean a = true;
    Character b;
    Integer c = 123;
    Double d = 3.14;
    String e = "string";

How can I use this wrapper classes? Do I need to import something? If so, how?