What are Operators in JavaScript
Operators are symbols or keywords that tell the JavaScript engine to perform some sort of actions. For example, the addition (+) symbol is an operator that tells JavaScript engine to add two variables or values, while the equal-to (==), greater-than (>) or less-than (<) symbols are the operators that tells JavaScript engine to compare two variables or values, and so on.
The following sections describe the different operators used in JavaScript.
JavaScript Arithmetic Operators
The arithmetic operators are used to perform common arithmetical operations, such as addition, subtraction, multiplication etc. Here’s a complete list of JavaScript’s arithmetic operators:
| Operator | Description | Example | Result |
|---|---|---|---|
+ | Addition | $x + $y | Sum of $x and $y |
- | Subtraction | $x - $y | Difference of $x and $y. |
* | Multiplication | $x * $y | Product of $x and $y. |
/ | Division | $x / $y | Quotient of $x and $y |
% | Modulus | $x % $y | Remainder of $x divided by $y |
The following example will show you these arithmetic operators in action:
var x = 10; var y = 4; alert(x + y); // 0utputs: 14 alert(x - y); // 0utputs: 6 alert(x * y); // 0utputs: 40 alert(x / y); // 0utputs: 2.5 alert(x % y); // 0utputs: 2
JavaScript Assignment Operators
The assignment operators are used to assign values to variables.
| Operator | Description | Example | Is The Same As |
|---|---|---|---|
= | Assign | x = y | x = y |
+= | Add and assign | x += $ | x = x + y |
-= | Subtract and assign | x -= y | x = x - y |
*= | Multiply and assign | x *= y | x = x * y |
/= | Divide and assign quotient | x /= y | x = x / y |
%= | Divide and assign modulus | x %= y | x = x % y |
The following example will show you these assignment operators in action:
var x; // Declaring Variable x = 10; alert(x); // Outputs: 1 x = 20; x += 30; alert(x); // Outputs: 50 x = 50; x -= 20; alert(x); // Outputs: 30 x = 5; x *= 25; alert(x); // Outputs: 125 x = 50; x /= 10; alert(x); // Outputs: 5 x = 100; x %= 15; alert(x); // Outputs: 10
JavaScript String Operators
There are two operators which can also used be for strings.
| Operator | Description | Example | Result |
|---|---|---|---|
+ | Concatenation | str1 + str2 | Concatenation of str1 and str2 |
+= | Concatenation assignment | str1 += str2 | Appends the str2 to the str1 |
JavaScript Incrementing and Decrementing Operators
The increment/decrement operators are used to increment/decrement a variable’s value.
| Operator | Name | Effect |
|---|---|---|
++x | Pre-increment | Increments x by one, then returns x |
x++ | Post-increment | Returns x, then increments x by one |
--x | Pre-decrement | Decrements x by one, then returns x |
x-- | Post-decrement | Returns x, then decrements x by one |
JavaScript Logical Operators
The logical operators are typically used to combine conditional statements.
| Operator | Name | Example | Result |
|---|---|---|---|
&& | And | x && y | True if both x and y are true |
|| | Or | x || y | True if either x or y is true |
! | Not | !x | True if x is not true |
JavaScript Comparison Operators
The comparison operators are used to compare two values in a Boolean fashion.
| Operator | Name | Example | Result |
|---|---|---|---|
== | Equal | x == y | True if x is equal to y |
=== | Identical | x === y | True if x is equal to y, and they are of the same type |
!= | Not equal | x != y | True if x is not equal to y |
!== | Not identical | x !== y | True if x is not equal to y, or they are not of the same type |
< | Less than | x < y | True if x is less than y |
> | Greater than | x > y | True if x is greater than y |
>= | Greater than or equal to | x >= y | True if x is greater than or equal to y |
<= | Less than or equal to | x <= y | True if x is less than or equal to y |