Question

Is there a way to declare an unsigned int in Java?

Or the question may be framed as this as well:
What is the Java equivalent of unsigned?

Just to tell you the context I was looking at Java’s implementation of String.hashcode(). I wanted to test the possibility of collision if the integer were 32 unsigned int.

Answer 1

Java does not have a datatype for unsigned integers.

You can define a long instead of an int if you need to store large values.

You can also use a signed integer as if it were unsigned. The benefit of two’s complement representation is that most operations (such as addition, subtraction, multiplication, and left shift) are identical on a binary level for signed and unsigned integers. A few operations (division, right shift, comparison, and casting), however, are different. As of Java SE 8, new methods in the Integer class allow you to fully use the int data type to perform unsigned arithmetic:

In Java SE 8 and later, you can use the int data type to represent an unsigned 32-bit integer, which has a minimum value of 0 and a maximum value of 2^32-1. Use the Integer class to use int data type as an unsigned integer. Static methods like compareUnsigned, divideUnsigned etc have been added to the Integer class to support the arithmetic operations for unsigned integers.

Note that int variables are still signed when declared but unsigned arithmetic is now possible by using those methods in the Integer class.