JavaScript provides 6 different operators to perform basic arithmetic operations on numbers.
+
: The addition operator is used to find the sum of numbers.
1 + 2; // => 3
2.5 + 3.9; // => 6.5
-
: The subtraction operator is used to find the difference between two numbers
19 - 2; // => 17
7.4 - 1.2; // => 6.2
*
: The multiplication operator is used to find the product of two numbers
7 * 5; // => 35
9.2 * 6.3; // => 57.959999999999994
/
: The division operator is used to divide two numbers.
Since JavaScript numbers are always floating-point numbers, there is no integer division.
8 / 2; // => 4
25 / 3; // => 8.333333333333334
%
: The remainder operator is used to find the remainder of a division performed.
40 % 4; // => 0
11 % 4; // => 3
-11 % 4; // => -3
**
: The exponentiation operator is used to raise a number to a power.
It is the equivalent of using Math.pow()
4 ** 3; // => 64
4 ** 1 / 2; // => 2
When using multiple operators in a line, JavaScript follows an order of precedence as shown in this precedence table. To simplify it to our context, JavaScript uses the PEDMAS (Parentheses, Exponents, Division/Multiplication, Addition/Subtraction) rule we've learnt in elementary math classes.
const result = 3 ** 3 + 9 * 4 / (3 - 1);
// => 3 ** 3 + 9 * 4/2
// => 27 + 9 * 4/2
// => 27 + 18
// => 45
Shorthand assignment operators are a shorter way of writing code conducting arithmetic operations on a variable, and assigning the new value to the same variable.
For example, consider two variables x
and y
.
Then, x += y
is same as x = x + y
.
Often, this is used with a number instead of a variable y
.
The 5 other operations can also be conducted in a similar style.
let x = 5;
x += 25; // x is now 30
let y = 31;
y %= 3; // y is now 1