An Introduction to Dragon/Lessons/Operators

Operators

In this chapter we will introduce the operators provided by the Dragon programming language.

Arithmetic Operators

The next table presents all of the arithmetic operators provided by the Dragon language. Assume variable x = 50 and variable y = 10, then:

+------------+---------------+----------+---------+
| Operator   | Description   | Example  | Result  |
+============+===============+==========+=========+
| +          |  Add          |  x+y     |  60     |
+------------+---------------+----------+---------+
| -          |	Subtract     |	x-y     |  40     |
+------------+---------------+----------+---------+
| *          |  Multiply     |	x*y     |  500    |
+------------+---------------+----------+---------+
| /          |  Divide	     |	x/y     |  5      |
+------------+---------------+----------+---------+
| %          |  Modulus	     |	x%y     |  0      | 
+------------+---------------+----------+---------+
| ++         |  Increment    |	x++     |  51     |
+------------+---------------+----------+---------+
| --         |  Decrement    |	x--     |  49     |
+------------+---------------+----------+---------+

Relational Operators

The next table presents all of the relational operators provided by the Dragon language. Assume variable x = 50 and variable y = 10, then:

+------------+---------------------+-------------+---------+
| Operator   | Description         | Example     | Result  |
+============+=====================+=============+=========+
| ==         |  Equal	           |    x == y   |  False  |
+------------+---------------------+-------------+---------+
| !=         |	Not Equal          |	x != y   |  True   |
+------------+---------------------+-------------+---------+
| >          |  Greater than       |	x > y    |  True   |
+------------+---------------------+-------------+---------+
| <          |  Less than          |	x < y    |  False  |
+------------+---------------------+-------------+---------+
| >=         |  Greater or Equal   |	x >= y   |  True   | 
+------------+---------------------+-------------+---------+
| <=         |  Less than or Equal |	x <= y   |  False  |
+------------+---------------------+-------------+---------+

Logical Operators

The next table presents all of the logical operators provided by the Dragon language. Assume variable x = true and variable y = false, then:

+------------+---------------------+-------------+---------+
| Operator   | Description         | Example     | Result  |
+============+=====================+=============+=========+
| &&	     |  Logical AND        |    x && y   |  false  |
+------------+---------------------+-------------+---------+
| ||         |	Logical OR         |	x || y   |  true   |
+------------+---------------------+-------------+---------+
| !	         |  Logical Not        |	!x       |  false  |
+------------+---------------------+-------------+---------+

Bitwise Operators

The next table presents all of the bitwise operators provided by the Dragon language. Assume variable x = 8 and variable y = 2, then:

+------------+-----------------------------+-------------+---------+
| Operator   | Description                 | Example     | Result  |
+============+=============================+=============+=========+
| &          |  Binary AND                 |    x & y    |  0      |
+------------+-----------------------------+-------------+---------+
| |          |	Binary OR                  |	x | y    |  10     |
+------------+-----------------------------+-------------+---------+
| ^          |  Binary XOR                 |	x ^ y    |  10     |
+------------+-----------------------------+-------------+---------+
| ~          |  Binary Ones Complement 	   |	~x       |  -9     |
+------------+-----------------------------+-------------+---------+
| <<         |  Binary Left Shift          |	x << y   |  32     | 
+------------+-----------------------------+-------------+---------+
| >>         |  Binary Right Shift         |	x >> y   |  2      |
+------------+-----------------------------+-------------+---------+

Assignment Operators

The next table presents all of the assignment operators provided by the Dragon language.

Assume variable x = 8, then:

+------------+-----------------------------+-------------+---------+
| Operator   | Description                 | Example     | Result  |
+============+=============================+=============+=========+
| =          |  Assignment                 |    x = 8    |  x=8    |
+------------+-----------------------------+-------------+---------+
| +=         |	Add AND assignment         |	x += 5   |  x=13   |
+------------+-----------------------------+-------------+---------+
| -=	     |  Subtract AND assignment    |	x -= 3   |  x=10   |
+------------+-----------------------------+-------------+---------+
| *=         |  Multiply AND assignment    |	x *= 2   |  x=20   |
+------------+-----------------------------+-------------+---------+
| /=         |  Divide AND assignment      |	x /= 3   |  x=6    |
+------------+-----------------------------+-------------+---------+
| %=         |  Modulus AND assignment     |	x %= 2   |  x=0    | 
+------------+-----------------------------+-------------+---------+
| <<=        |	Left shift AND assignment  |	x <<= 2  |  x=0    |
+------------+-----------------------------+-------------+---------+
| >>=	     |  Right shift AND assignment |	x >>= 2  |  x=0    |
+------------+-----------------------------+-------------+---------+
| &=         |  Bitwise AND assignment     |	x &= 4   |  x=0    |
+------------+-----------------------------+-------------+---------+
| |=         |  Bitwise OR and assignment  |	x |= 3   |  x=3    |
+------------+-----------------------------+-------------+---------+
| ^=         |  Bitwise XOR and assignment |	x ^= 4   |  x=7    |
+------------+-----------------------------+-------------+---------+

Misc Operators

==============	======================================================================
Operator        Description
==============	======================================================================
Start:End       create list contains items from start to end
[list items]    define list items
list[index]     access list item
==============	======================================================================

Operator Precedence

The next table presents operators from highest precedence (evaluated first) to lowest precedence.

+----------------------------------------------------------------+
| Operator                                                       |
+================================================================+
| .  []   ()     {}                                              |
+----------------------------------------------------------------+
| -  ~  :Literal  [list items]                                   |
+----------------------------------------------------------------+
| ++   --                                                        |
+----------------------------------------------------------------+
| Start:End                                                      |
+----------------------------------------------------------------+
| * /  %                                                         |
+----------------------------------------------------------------+
| + -                                                            |
+----------------------------------------------------------------+
| <<   >>                                                        |
+----------------------------------------------------------------+
| &                                                              |
+----------------------------------------------------------------+
| \|  ^	                                                         |
+----------------------------------------------------------------+
| <  >  <=  >=                                                   |
+----------------------------------------------------------------+
| =  !=                                                          |
+----------------------------------------------------------------+
| not                                                            |
+----------------------------------------------------------------+
| and   or                                                       |
+----------------------------------------------------------------+
| Assignment = += -= \*= /= %= >>= <<= &= ^= \|=                 |
+----------------------------------------------------------------+

Example:

	show 3+5*4	// prints 23