JS TutorialLesson #12

JavaScript Operators

The Assignment Operator = assigns values

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


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JavaScript Assignment

The Assignment Operator (=) assigns a value to a variable:

Assignment Examples

Example Code

javascript
Try it Yourself
let x = 10;

JavaScript Addition

The Addition Operator (+) adds numbers:

Adding

Example Code

javascript
Try it Yourself
let x = 5;

let y = 2;

let z = x + y;

JavaScript Multiplication

The Multiplication Operator (*) multiplies numbers:

Multiplying

Example Code

javascript
Try it Yourself
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

Example Code

javascript
Try it Yourself
let a = 3;

let x = (100 + 50) * a;
OperatorDescription
+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

Example Code

javascript
Try it Yourself
let text1 = "John";

let text2 = "Doe";

let text3 = text1 + " " + text2;

The += assignment operator can also be used to add (concatenate) strings:

Example

Example Code

javascript
Try it Yourself
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

Example Code

javascript
Try it Yourself
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

Example Code

javascript
Try it Yourself
let x = 10;
x += 5;
OperatorExampleSame As
=x = yx = y
+=x += yx = x + y
-=x -= yx = x - y
*=x *= yx = x * y
/=x /= yx = x / y
%=x %= yx = x % y
=x = yx = 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

Example Code

javascript
Try it Yourself
let x = 5;

let result = x > 8;
OperatorDescriptionExample
==equal tox == 5
===equal value and equal typex === 5
!=not equalx != 5
!==not equal value or not equal typex !== 5
>greater thanx > 5
=greater than or equal tox >= 5

| Comparison operators are fully described in the > JS Comparisons chapter.


JavaScript Logical Operators

OperatorDescription
&&logical and
\\logical or
!logical not
Logical operators are fully described in the > JS Logical chapter.


Interactive Code Examples

Assignment Examples

javascript
Try it Yourself
JavaScript syntax and algorithm demonstration.
let x = 10;

Adding

javascript
Try it Yourself
JavaScript syntax and algorithm demonstration.
let x = 5;

let y = 2;

let z = x + y;

Multiplying

javascript
Try it Yourself
JavaScript syntax and algorithm demonstration.
let x = 5;

let y = 2;

let z = x * y;

Arithmetic Operators Example

javascript
Try it Yourself
JavaScript syntax and algorithm demonstration.
let a = 3;

let x = (100 + 50) * a;

JS Example 5

javascript
Try it Yourself
JavaScript syntax and algorithm demonstration.
let text1 = "John";

let text2 = "Doe";

let text3 = text1 + " " + text2;

JS Example 6

javascript
Try it Yourself
JavaScript syntax and algorithm demonstration.
let text1 = "What a very ";

text1 += "nice day";