What primitive data types exist in Kotlin and Java?

In Kotlin:

• Byte (8-bit Int)
• Short (16-bit Int)
• Int (32-bit Int)
• Long (64-bit Int)
• Float (32-bit Float)
• Double (64-bit Float)
• Boolean (true/false)
• Char (1 character)

In Java:

• byte (8-bit signed two's complement integer)
• short (16-bit signed two's complement integer)
• int (32-bit signed two's complement integer)
• long (64-bit signed two's complement integer)
• float (single-precision 32-bit IEEE 754 floating point)
• double (double-precision 64-bit IEEE 754 floating point)
• boolean (true and false values)
• char (16-bit Unicode character)

Kotlin uses wrapper objects for primitive types in most cases, but the compiler optimizes them using JVM primitives where it is efficient. Java has a clear separation between primitives and wrapper objects.