Operators in JavaScript: Types and Usage Explained
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Table of Content:
Following operators available in JavaScript:
- Assignment operators
- Arithmetic operators
- Comparison operators
- Logical operators
- String operators
- Conditional operators
Assignment Operators
- Like most programming languages,
=
is the assignment operator - Variables can be declared either by key
var
and value OR simply by assigning values directly. Ex –var x = 42
; ORx = 42 ;
- Explicit type declaration is not necessary.
- Same variable can be assigned values of different data types. To know the type of a variable, use
typeof
operator. Ex –
var x = "hello"; var x = true; console.log(typeof x); //returns Boolean
Comparison Operators
- JavaScript has operators like
<, >, !=, >=, <=
to compare 2 operands. - What is unique about JavaScript is the
==
and===
operators? ==
compares the operands and returnstrue
without considering their data type. Ex:var a = 10, b= “10”;
if(a==b)
results intrue
due to the same value they carry, but ignores data types differentiation.- However,
if(a===b)
results infalse
as they are of different data types.
Standard Arithmetic Operators
- Addition
+
Ex:[5 + 8]
- Subtraction
-
Ex:[49 – 38]
- Division
/
Ex:[ 49 / 7]
- Multiplication
*
Ex:[28 * 2]
More on Arithmetic Operators
- Modulus
%
to return the remainder of a division – Ex:50 % 7
is 1 - Increment
++
to increment the operand itself by 1 – Ex: If x=4,x++
evaluates to5
- Decrement
--
to decrement the operand itself by 1 – Ex: if x= 10,x—-
evaluates to9
Logical Operators
AND &&
, OR ||
, NOT !
are the logical operators often used during conditional statements to test logic between variables.
Expr1 && Expr2
returns true if both are true, else returns false.Expr1 || Expr2
returns true if either is true.!Expr1
operates on single operand to convert true to false and vice versa.
String Operator
Operator +
is used to concatenate strings. x = "Hello"; y = " World "; x + y; /* Returns “Hello World” */
While concatenating, JavaScript treats all data types as strings even if values are of different data types.
x = "Hello"; y = 100; z = 333; x + y + z; /* Returns “Hello100333” */