JS Arithmetic
JavaScript Arithmetic Operators
Arithmetic operators perform operations on integers (literals or variables).
| Operator | Description |
|---|---|
| + | Addition |
| – | Subtraction |
| * | Multiplication |
| ** | Exponentiation (ES2016) |
| / | Division |
| % | Modulus (Remainder) |
| ++ | Increment |
| — | Decrement |
Arithmetic Operations
A typical arithmetic procedure works with two numbers.
The two numbers could be literals.
Example
let x = 100 + 50;
or variables:
Example
let x = a + b;
or expressions:
Example
let x = (100 + 50) * a;
Operators and Operands
The numbers used in an arithmetic operation are referred to as operands.
An operator defines the operation that will be done between the two operands.
| Operand | Operator | Operand |
|---|---|---|
| 100 | + | 50 |
Adding
To add numbers, use the addition operator (+):
Example
let x = 5;
let y = 2;
let z = x + y;
Subtracting
The subtraction operator (–) subtracts values.
Example
let x = 5;
let y = 2;
let z = x - y;
Multiplying
The multiplication operator (*) multiplyes numbers.
Example
let x = 5;
let y = 2;
let z = x * y;
Dividing
The division operator (/) divides numbers.
Example
let x = 5;
let y = 2;
let z = x / y;
Remainder
The modulus operator (%) returns the division remainder.
Example
let x = 5;
let y = 2;
let z = x % y;
In arithmetic, dividing two integers results in a quotient and a remainder.
In mathematics, a modulo operation yields the remainder of an arithmetic division.
Incrementing
The increment operator (++) increments numbers.
Example
let x = 5;
x++;
let z = x;
Decrementing
The decrement operator (—) decrements numbers.
Example
let x = 5;
x--;
let z = x;
Exponentiation
The exponentiation operator (**) multiplies the first operand to the power of the second.
Example
let x = 5;
let z = x ** 2;
x ** y yields the same output as Math.pow(x,y):
Example
let x = 5;
let z = Math.pow(x,2);
Operator Precedence
Operator precedence refers to the order in which operations are performed in an arithmetic expression.
Example
let x = 100 + 50 * 3;
Is the result of the preceding example the same as 150 * 3, or 100 + 150?
Is addition or multiplication done first?
Multiplication comes first, as it does in regular school mathematics.
Multiplication (*) and division (/) take precedence over addition and subtraction.
In addition, parenthesis can be used to shift the precedence, just like in school mathematics.
When employing parentheses, the operations inside them are computed first:
Example
let x = (100 + 50) * 3;
When multiple operations have the same priority (such as addition and subtraction or multiplication and division), they are computed from left to right.
Example
let x = 100 + 50 - 3;
let x = 100 / 50 * 3;
