In Java, both int
and Integer
are used to represent integer values, but there are some important differences between them.
int
is a primitive data type in Java, which means it is a basic type that is built into the language. It represents a 32-bit signed integer value and can hold values from -2^31 to 2^31-1. Because int
is a primitive type, it is faster and takes less memory than the Integer
object.
On the other hand, Integer
is a wrapper class that provides functionality to convert an int
to an object and vice versa. Integer
objects are used when an object reference is required, such as when working with collections or when passing integers to methods that require objects.
One advantage of using Integer
over int
is that it provides additional methods and constants for working with integers, such as parseInt()
for converting a string to an integer and MAX_VALUE
and MIN_VALUE
for getting the maximum and minimum integer values.
Another important difference between int
and Integer
is that int
is a primitive type, so it cannot be null
. In contrast, Integer
is an object, so it can be null
. This can be useful in situations where you need to represent the absence of a value.
In general, you should use int
when you need to represent an integer value and don’t need the additional functionality provided by Integer
, and use Integer
when you need to work with objects, collections, or when you need to take advantage of the additional methods and constants provided by the class.