JavaScript Arithmetic
JavaScript Arithmetic Operators
Arithmetic operators perform arithmetic on numbers (literals or variables).
Operator
Description
+
Addition
-
Subtraction
*
Multiplication
**
Exponentiation (ES2016)
/
Division
%
Modulus (Remainder)
++
Increment
--
Decrement
Arithmetic Operations
A typical arithmetic operation operates on two numbers.
The two numbers can be literals:
Example
let x = 100 + 50;
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or variables:
Example
let x = a + b;
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or expressions:
Example
let x = (100 + 50) * a;
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Operators and Operands
The numbers (in an arithmetic operation) are called operands.
The operation (to be performed between the two operands) is defined by an operator.
Operand
Operator
Operand
100
+
50
Adding
The addition operator (+) adds numbers:
Example
let x = 5;
let y = 2;
let z = x + y;
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Subtracting
The subtraction operator (-) subtracts numbers.
Example
let x = 5;
let y = 2;
let z = x - y;
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Multiplying
The multiplication operator (*) multiplies numbers.
Example
let x = 5;
let y = 2;
let z = x * y;
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Dividing
The division operator (/) divides numbers.
Example
let x = 5;
let y = 2;
let z = x / y;
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Remainder
The modulus operator (%) returns the division remainder.
Example
let x = 5;
let y = 2;
let z = x % y;
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In arithmetic, the division of two integers produces a quotient
and a remainder.
In mathematics, the result of a modulo operation is the remainder of an arithmetic division.
Incrementing
The increment operator (++) increments numbers.
Example
let x = 5;x++;
let z = x;
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Decrementing
The decrement operator (--) decrements numbers.
Example
let x = 5;
x--;
let z = x;
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Exponentiation
The exponentiation operator (**) raises the first operand to the power of the second operand.
Example
let x = 5;
let z =
x ** 2;
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x ** y produces the same result as Math.pow(x,y):
Example
let x = 5;
let z =
Math.pow(x,2);
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Operator Precedence
Operator precedence describes the order in which operations are performed in
an arithmetic expression.
Example
let x = 100 + 50 * 3;
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Is the result of example above the same as 150 * 3, or is it the same as 100
+ 150?
Is the addition or the multiplication done first?
As in traditional school mathematics, the multiplication is done first.
Multiplication (*) and division (/) have higher precedence than
addition (+) and subtraction (-).
And (as in school mathematics) the precedence can be changed by using
parentheses.
When using parentheses, the operations inside the parentheses are computed
first:
Example
let x = (100 + 50) * 3;
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When many operations have the same precedence (like addition and
subtraction or multiplication and division), they are computed from left to
right:
Examples
let x = 100 + 50 - 3;
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let x = 100 / 50 * 3;
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Note
For a full list of operator precedence values go to:
JavaScript Operator Precedence Values.
Test Yourself With Exercises
Exercise:
Divide 10 by 2, and alert the result.
alert(10 2);
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Start the Exercise
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Reference: https://www.w3schools.com/js/js_arithmetic.asp