Operators in JS

Operators in Java Script


An expression is a combination of operators operands that can be evaluated. It may also include function calls which return values.

Examples

x = 7.5 // a numeric literal
“Hello India!” // a string literal
false // a Boolean literal
{feet:10, inches:5} // an object literal
[2,5,6,3,5,7] // an array literal
v= m + n; // the variable v
tot // the variable tot

ARITHMETIC OPERATORS

These are used to perform arithmetic/mathematical operations like subtraction, division, multiplication etc. Arithmetic operators work on one or more numerical values (either literals or variables) and return a single numerical value. The basic arithmetic operators are:


OperatorOperator
+ (Addition) 
- (Subtraction)
* (Multiplication)
/ (Division)
% (Modulus) 


Examples

var s = 10 + 20; // result: s=30
var h = 50 * 4; // result: h = 200
var d = 100 / 4; // result: d = 25
var r = 72 % 14; // result: r=2

Increment and decrement operators

These operators are used for increasing or decreasing the value of a variable by 1. Calculations performed using these operators are very fast.

++ Increment (By One)

-- Decrement (By One)

Example

var a = 15;
a++; // result: a = 16
var b = 20;
b—; // result: b = 19

ASSIGNMENT OPERATORS

It assigns the value of its right operand to its left operand. This operator is represented by equal sign(=).

Example

x = 100; // This statement assigns the value 100 to x.

JavaScript also supports shorthand operator for standard operations.

The shorthand operator with example :

Shorthand operator
Example
is equivalent to
+=a + = b
a = a + b
-=a - = b
a = a - b
*=a * = b
a = a * b
/=a / = b
a = a / b
%=a % = b
a = a % b


RELATIONAL (COMPARISON) OPERATORS

Relational Operators are some symbols which return a Boolean value true or false after evaluating the condition. For example x > y; returns a value true is value of variable x is greater than variable y.

Basic JavaScript comparison operators are given in the table below :

Operator
Description
Example
= =
is equal to
4 = = 8 returns false
! =
is not equal to
4 ! = 8 returns true
>
is greater than
8 > 4 returns true
<
is less than
8 > 4 returns false
< =
is less than or equal to
8 < = 4 returns false
> =
is greater than or equal to
8 > = 4 returns true

Relational operators are functional for strings as well. The comparison takes place in alphabetical order. This alphabetical order is based on ASCII number. For example :


Statement 
Output
“zero” < “one”
false
“Zero” < “one”
true
10 < 5
false, numeric comparison.
“10” < “5”
true, string comparison.
“10” < 5
false, numeric comparison;
“Ten” < 5
Error occurs, “Ten” can not be converted into a number


LOGICAL OPERATORS

Logical operators are used for combining two or more conditions. JavaScript has following three logical operators :

Operator
Description with Example
&& (AND)
returns true if both operands are true else it return false.
| | (OR)
returns false if both operands are false else it returns true.
! (NOT)
returns true if the operand is false and false if operand is true.


CONCATENATION OPERATOR

The + operator concatenates two string operands. The + operator gives priority to string operands over numeric operands It works from left to right. The results depend on the order in which operations are performed.

For example :


Statement
Output
“Good” + “Morning”
“GoodMorning”
“5” + “10”
“510”
“Lucky” + 7
“Lucky7”
4 + 7 + “Delhi”
“11Delhi”
“Mumbai” + 0 +0+ 7
“Mumbai007”


Conditional Operator ( ? : )

The conditional operator is a special JavaScript operator that takes three operands. Hence, it is also called ternary operator. A conditional operator assigns a value to a variable based on the condition.

Syntax

var_name = (condition) ? v_1 : v_2

If (condition) is true, the value v_1 is assigned to the variable, otherwise, it assigns the value v_2 to the variable.

For example

status = (age >= 18) ? “adult” : “minor”

This statement assigns the value “adult” to the variable status if age is eighteen or more. Otherwise, it assigns the value “minor” to status.

New Operator:

new operator is used to create an instance and allocate memory to a user-defined or predefined object types.

Syntax

ObjectName = new objectType ( param1 [,param2] ...[,paramN])

Example

d = new Date(); // date assigns to object d
r = new rectangle(4, 5, 7, 8);


Delete Operator

The delete operator de-allocates (releases) the memory space that was allocated using the new operator by deleting an object, an object’s property or an element from an array.

The syntax is

delete object_name
delete object_name.property
delete array_name[index]

delete operator can be used to delete variables declared implicitly but not those declared with the var statement. The delete operator returns true if the operation is possible; it returns false if the operation is not possible.

Question : What is difference between java and javascript

Answer : Some people think that Java and JavaScript are same but both are two completely different languages. Java is a general-purpose objectoriented programming language from Sun Microsystems where as JavaScript is an object-based scripting language. Script refers to short programming statements to perform a task.

Programs

java script code to show the reservation system of XYZ

View Solution


java Script Application for Student attendance

View Solution


java script function max to find largest number

View Solution


JavaScript code that calculates the squares and cubes from 0 to 10

View Solution


JavaScript code to design a simple calculator to perform the following operations sum product difference and quotient

View Solution


CCC Online Test 2021 CCC Practice Test Hindi Python Programming Tutorials Best Computer Training Institute in Prayagraj (Allahabad) Best Java Training Institute in Prayagraj (Allahabad) Best Python Training Institute in Prayagraj (Allahabad) O Level NIELIT Study material and Quiz Bank SSC Railway TET UPTET Question Bank career counselling in allahabad Sarkari Naukari Notification Best Website and Software Company in Allahabad Website development Company in Allahabad Sarkari Exam Quiz