Programming Fundamentals/Arithmetic Operators
Overview
[edit  edit source]The basic arithmetic operations are addition, subtraction, multiplication, and division. Arithmetic is performed according to an order of operations.^{[1]}
Discussion
[edit  edit source]An operator performs an action on one or more operands. The common arithmetic operators are:
Action  Common Symbol 
Addition  +

Subtraction  

Multiplication  *

Division  /

Modulus (associated with integers)  %

These arithmetic operators are binary that is they have two operands. The operands may be either constants or variables.
age + 1
This expression consists of one operator (addition) which has two operands. The first is represented by a variable named age and the second is a literal constant. If age had a value of 14 then the expression would evaluate (or be equal to) 15.
These operators work as you have learned them throughout your life with the exception of division and modulus. We normally think of division as resulting in an answer that might have a fractional part (a floatingpoint data type). However, division, when both operands are of the integer data type, may act differently. Please refer to the next section on “Integer Division and Modulus”.
Arithmetic Assignment Operators
[edit  edit source]Many programming languages support a combination of the assignment (=
) and arithmetic operators (+
, 
, *
, /
, %
). Various textbooks call them “compound assignment operators” or “combined assignment operators." Their usage can be explained in terms of the assignment operator and the arithmetic operators. In the table, we will use the variable age and you can assume that it is of integer data type.
Arithmetic assignment examples:  Equivalent code: 

age += 14;

age = age + 14;

age = 14;

age = age  14;

age *= 14;

age = age * 14;

age /= 14;

age = age / 14;

age %= 14;

age = age % 14;

Pseudocode
[edit  edit source]Function Main ... This program demonstrates arithmetic operations. Declare Integer a Declare Integer b Assign a = 3 Assign b = 2 Output "a = " & a Output "b = " & b Output "a + b = " & a + b Output "a  b = " & a  b Output "a * b = " & a * b Output "a / b = " & a / b Output "a % b = " & a % b End
Output
[edit  edit source]a = 3 b = 2 a + b = 5 a  b = 1 a * b = 6 a / b = 1.5 a % b = 1