JavaScript Operators ⚙️
Operators are an important part of programming. In JavaScript operators are symbols or keywords used to perform operations on values and/or variables.
There are various types of operators in JavaScript:
Arithmetic Operators
Used to perform mathematical calculations such as addition, subtraction, division, etc.
| Operator | Meaning | Example |
|---|---|---|
+ |
Addition: adds 2 numbers | 5 + 3 → 8 |
- |
Subtraction: subtracts the second number from first one | 10 - 3 → 7 |
* |
Multiplication: multiplies 2 numbers | 4* 3 → 12 |
/ |
Division: divides the first number by second number | 9 / 3 → 3 |
% |
Modulus: also known as remainder operator, returns the remainder left over after dividing first number by second number | 5 % 2 → 1 |
Comparison Operators
Used to compare 2 values and return a boolean, either true or false.
| Operator | Meaning | Example |
|---|---|---|
== |
Equal to: used to checks values | 15 == "15" → true |
=== |
Strict equal: used to check value as well as type | 15 === "15" → false because number 15 is not equal to string 15 |
!= |
Not equal | 5 != 3 → true |
> |
Greater than | 8 > 5 → true |
< |
Less than | 3 < 9 → true |
Difference between == and ===
Eg. if we do, console.log(5 == "5");
Console will print true because it has not checked the type of the value. So, it shows that 5 is equal to 5.
but if, console.log(5 === "5");
Console will print false because now the type of the value has been checked, they are different one is number and another one is string.
Using === is safe because because it checks for strict equality and prevents errors.
Logical Operators
Used to combine or modify, to determine equality or difference between the values.
There are 3 types of logical operators: &&, | |, !
&& returns true if both conditions are true.
Eg. let age = 23;
let canVote = true;
console.log(age> 18 && canVote);
Console prints true since both conditions are satisfied.
| | returns true if at least one condition is true.
Eg. let isWeekend = false;
let isHoliday = true;
console.log(isWeekend || isHoliday);
Console prints true since one condition is true.
! reverses the value.
Eg. let isAdult = true;
console.log(!isAdult);
Console prints false since ! reverses the value.
Assignment Operators
Used to assign values to variables. They can also perform some additional operations as well while assigning a value.
The basic assignment operator is =, which assigns the value.
Eg. If i want to write that value of x is 5, I will write, x = 5.
If i want to add something to x we can use += operator,
Eg. x+=5 which means x = x+ 5;
Similarly we can, subtract to x by writing x-= 5 which means x = x-5.
let x =5;
x+=5;
console.log(x); // output is 10
x-=5;
console.log(x); // output is 5
These operators give a clean look to our code which is easier to read and maintain.
Assignment
Arithmetic operations on two numbers:
const a = 5;
const b= 2;
console.log(a+b); //output is 7
console.log(a-b); //output is 3
console.log(a*b); //output is 10
console.log(a/b); //output is 2.5
Comparing two values using both == and === :
console.log(12=="12"); //output is true
console.log(12==="12"); //output is false
Using logical operators:
let age = 23;
let hasLicense = true;
if (age >= 18 && hasLicense){
console.log("You can drive");
}; //console prints You can drive