What is the difference between a Java int and a Java Integer?

In Java, 'int' is a primitive data type that represents a 32-bit signed integer. It is a basic data type that is used to store numerical values.

While 'Integer' is a wrapper class for the 'int' primitive data type. It is an object that contains a single field of type 'int'. The 'Integer' class provides additional methods for working with integers, such as converting an 'int' to a 'String' or comparing two 'Integer' objects.

Here are some key differences between 'int' and 'Integer':

• int is a primitive data type, whereas Integer is a reference data type.
• int variables are stored in the stack memory, whereas Integer objects are stored in the heap memory.
• int variables are directly used in arithmetic and comparison operations, whereas Integer objects need to be unwrapped using the intValue() method before they can be used in arithmetic or comparison operations.
• int variables cannot be null but Integer class objects can be null.
• int variables are more efficient to work with than Integer objects because they require less memory and have fewer method calls.