Operators in JavaScript!

Elisa McDonald — Thu, 04 May 2023 19:06:36 +0000

What are Operators?

Operators are special symbols that act on data. They're used to perform operations on values or variables by assigning them to a variable, comparing them, or using them in arithmetic operations.

Arithmetic Operators:

Arithmetic operators are used to perform arithmetic on values (either literal or variables).

+ addition
- subtraction
* multiplication
** exponentiation
/ division
% modulus aka remainder
++ increment
-- decrement

Examples of arithmetic operators being used:

1 + 1 = 2
2 - 1 = 1
2 * 2 = 4
3 ** 2 = 9
4 / 2 = 2
5 % 2 = 1
5++ = 6
5-- = 4

Assignment Operators:

Assignment operators assign a value to a variable.

Examples of assignment operators being used:

x = 2
x += 2 // reassigns x to whatever it was + 2
x -= 2 // reassigns x to whatever it was - 2
x *= 2
x /= 2
x %= 2
x **= 2

Comparison Operators:

Comparison operators compare two values to determine equality or difference and evaluate to a boolean aka true or false.

== loosely equal to
=== strictly equal to

!= loosely not equal to
!== strictly not equal to

The difference between loosely equal / not equal & strictly equal to:
Loosely checks if just value are equal.
Strictly checks if both the value and data type are equal.

Helpful Tip: Don't use non-strict comparison unless there's a good reason to which is almost never!

> greater than
< less than
>= greater than or equal to
<= less than or equal to

Examples of comparison operators being used:

x = 5
y = 10

x == 5 // returns true
x == '5' // returns true

x === 5 // returns true
x === '5' // returns false

y != 10 // returns false
y != '10' // returns false

y !== 10 // returns false
y !== '10' // returns true

x > 10 // returns false
x < 10 // returns true

y >= 10 // returns true
y <= 10 // returns true

Logical Operators:

Logical operators compare two variables or values and determine the logic whether it's true or false

&& and
|| or
! not

Examples of logical operators being used:

x = 2 
y = 6

// if all inequalities are true it returns true
x < y && y > 8

// if at least one of the inequalities are true it returns true
x > y || y < 4

// logical opposite
!x === 3

Ternary Operators:

The only operator that takes 3 operands: a condition followed by a ? then an expression to execute if the condition is truthy followed by a : and then the expression to execute if the condition is falsy. The ternary operator is an alternative to using an if else statement.

let number = 99;

let lessThan100 = number < 100 ? "Less than 100!" : "Sorry your number is not under 100."

console.log(lessThan100); // "Less than 100!"

Conclusion:

Operators are important tools in JavaScript for performing various operations on data. Each type of operator serves a specific purpose. Understanding how to use operators can help write more efficient and readable code.

Happy coding! :)

DEV Community: Elisa McDonald