Java - long - Long (integer 64 bit)
Table of Contents
About
In Java, the long data type stores integer on 64 bit while the integer data type stores integer on 32bit.
The primitive wrapper Long is a subclass of Number in java
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Implementation
Primitive Integer
Long is an integer that is encoded with 64 bit but you have also int on 32 bit.
| Primitive Type | Primitive Wrapper | Stored in a word of | min | max |
|---|---|---|---|---|
| int | Integer | 32 bits | <math>-2^{31}</math>
-2,147,483,648 | <math>+2^{31}-1</math>
-2,147,483,647 |
| long | Long | 64 bits | <math>-2^{63}</math>
-9,223,372,036,854,775,807 | <math>+2^{63-1}</math>
4.611.686.018.427.387.904 |
Long
- java/util/concurrent/atomic/AtomicLong - A long value that may be update atomically - support increment function also
Management
Initialization
- From a literal
long = 1.073.741.824L;
- From a variable
long = (long)a;
- from an integer
Long i = theinteger.longValue()
- from an int
Long i = Long.valueOf(3);
Operation
Number - (Arithmetical | Numerical | Mathematical) Operators on long
The operations are done in the largest data type required to handle all of the current values.
| For the below mathematics Operations | The operation is a |
|---|---|
| int (operator) int | integer operation |
| int (operator) long | long operation |
Example:
- a long operation
long i = (int)1 * (long)2
- a int operation
long i = (int)1 * (int)2
To Int
- from a long object to an integer
Long theLong;
Integer i = theLong.intValue()
- or from a long primitive
Math.toIntExact(long)