Example
Assign values to variables and add them together:
let x = 5; // assign the value 5 to x
let y = 2; // assign the value 2 to y
let z = x + y; // assign the value 7 to z [5 + 2]
Try it Yourself »
The assignment operator [=
] assigns a value to a variable.
The addition operator [+
] adds numbers:
The multiplication operator [*
] multiplies numbers.
Types of JavaScript Operators
There are different types of JavaScript operators:
- Aritmetic Operators
- Assignment Operators
- Comparison Operators
- Logical Operators
- Conditional Operators
- Type Operators
JavaScript Arithmetic Operators
Arithmetic operators are used to perform arithmetic on numbers:
+ | Addition |
- | Subtraction |
* | Multiplication |
** | Exponentiation [ES2016] |
/ | Division |
% | Modulus [Division Remainder] |
++ | Increment |
-- | Decrement |
Arithmetic operators are fully described in the JS Arithmetic chapter.
JavaScript Assignment Operators
Assignment operators assign values to JavaScript variables.
= | x = y | x = y |
+= | x += y | x = x + y |
-= | x -= y | x = x - y |
*= | x *= y | x = x * y |
/= | x /= y | x = x / y |
%= | x %= y | x = x % y |
**= | x **= y | x = x ** y |
The addition assignment operator [+=
] adds a value to a variable.
Assignment operators are fully described in the JS Assignment chapter.
Adding JavaScript Strings
The +
operator can also be used to add [concatenate] strings.
Example
let text1 = "John";
let text2 = "Doe";
let text3 = text1 + " " +
text2;
The result of text3 will be:
John Doe
Try it Yourself »
The +=
assignment operator can also be used to add [concatenate] strings:
Example
let text1 = "What a very ";
text1 += "nice day";
The result of text1 will be:
What a very nice day
Try it Yourself »
When used on strings, the + operator is called the concatenation operator.
Adding Strings and Numbers
Adding two numbers, will return the sum, but adding a number and a string will return a string:
Example
let x = 5 + 5;
let y = "5" + 5;
let z = "Hello" + 5;
The result of x, y, and z will be:
10
55
Hello5
Try it Yourself »
If you add a number and a string, the result will be a string!
JavaScript Comparison Operators
== | equal to | ||||
=== | equal value and equal type | ||||
!= | not equal | ||||
!== | not equal value or not equal type | ||||
> | greater than | ||||
< | less than | ||||
>= | greater than or equal to | ||||
1 | 0101 >> 1 | 0010 | 2 | ||
>>> | unsigned right shift | 5 >>> 1 | 0101 >>> 1 | 0010 | 2 |
The examples above uses 4 bits unsigned examples. But JavaScript uses 32-bit signed numbers.
Because of this, in JavaScript, ~ 5 will not return 10. It will return -6.
~00000000000000000000000000000101 will return 11111111111111111111111111111010
Bitwise operators are fully described in the JS Bitwise chapter.