Operators are for Mathematical and Logical Computations
The Assignment Operator = assigns values
The Addition Operator + adds values
The Multiplication Operator * multiplies values
The Comparison Operator > compares values
JavaScript Assignment
The Assignment Operator ( = ) assigns a value to a variable:
Assignment Examples
let x = 10;JavaScript Addition
The Addition Operator ( + ) adds numbers:
Adding
let x = 5;
let y = 2;
let z = x + y;JavaScript Multiplication
The Multiplication Operator ( * ) multiplies numbers:
Multiplying
let x = 5;
let y = 2;
let z = x * y;Types of JavaScript Operators
There are different types of JavaScript operators:
- Arithmetic Operators
- Assignment Operators
- Comparison Operators
- Logical Operators
- And more ...
JavaScript Arithmetic Operators
Arithmetic Operators are used to perform arithmetic on numbers:
Arithmetic Operators Example
let a = 3;
let x = (100 + 50) * a;| Operator | Description |
|---|---|
| + | Addition |
| - | Subtraction |
| * | Multiplication |
| ** | Exponentiation |
| / | Division |
| % | Modulus (Division Remainder) |
| ++ | Increment |
| -- | Decrement |
Arithmetic operators are fully described in the JS Arithmetic chapter.
JavaScript String Addition
The + can also be used to add (concatenate) strings:
Example
let text1 = "John";
let text2 = "Doe";
let text3 = text1 + " " + text2;The += assignment operator can also be used to add (concatenate) strings:
Example
let text1 = "What a very ";
text1 += "nice day";When used on strings, the + operator is called the concatenation operator.
Adding Strings and Numbers
Adding two numbers, will return the sum as a number like 5 + 5 = 10.
Adding a number and a string, will return the sum as a concatenated string like 5 + "5" = "55".
Example
let x = 5 + 5;
let y = "5" + 5;
let z = "Hello" + 5;If you add a number and a string, the result will be a string!
JavaScript Assignment Operators
Assignment operators assign values to JavaScript variables.
The Addition Assignment Operator ( += ) adds a value to a variable.
Assignment
let x = 10;
x += 5;| Operator | Example | Same As |
|---|---|---|
| = | 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 |
Assignment operators are fully described in the JS Assignment chapter.
JavaScript Comparison Operators
Comparison operators are used to compare two values .
Comparison operators always return true or false .
Example
let x = 5;
let result = x > 8;| Operator | Description | Example |
|---|---|---|
| == | equal to | x == 5 |
| === | equal value and equal type | x === 5 |
| != | not equal | x != 5 |
| !== | not equal value or not equal type | x !== 5 |
| > | greater than | x > 5 |
| < | less than | x < 5 |
| >= | greater than or equal to | x >= 5 |
| <= | less than or equal to | x <= 5 |
All the comparison operators above can also be used on strings:
Example
let text1 = "A";
let text2 = "B";
let result = text1 < text2;Note that strings are compared alphabetically.
Comparison operators are fully described in the JS Comparisons chapter.
JavaScript Logical Operators
| Operator | Description |
|---|---|
| && | logical and |
| logical or | |
| ! | logical not |
Logical operators are fully described in the JS Logical chapter.