Operators in Javascript

Javascript Operators

Operators are simply some functions having a arithmatic, logical or bitwise property. To start with, we will to through arithmetic operators first as we know maths.

Arithmatic Operators

We are quite familiar with some of the operators but we’ll learn each on in detail.

Addition

var num1 = 10;
var num2 = 20;
var total = num1+num2;		//total = 20

Here, total will hold the value of sum of the numbers.

Substraction

var num1 = 10;
var num2 = 20;
var total = num1-num2;		//total = -10

Here, total will hold the value of difference of the numbers, with sign, (-) in this case.

Multiplication

var num1 = 10;
var num2 = 20;
var total = num1*num2;		//total = 200

Here, total will hold the value of multiplication of the numbers.

Division

var num1 = 10;
var num2 = 20;
var total = num1/num2;		//total = 0.5

Here, total will hold the value of quotient. 0.5 in this case.

Modulus

var num1 = 10;
var num2 = 20;
var total = num1%num2;		//total = 10

Here, total will hold the value of remainder.10 in this case.

Assignment

var num1 = 10;
var num2;
var num2 = num1;		//num2 = num1 = 10

Here, num2 will hold the value of num1. The assignment is done from right to left hand side. Simple Maths, isn’t it.

Increment

var num = 10;
var total = num++;		//total = 11
var total = num+=4;		//total = 11+4 = 15

Increment operator is just like addition, but used when you need to add a numeric value to the variable itself.

Decrement

var num = 10;
var total = num--;		//total = 9
var total = num-=2;		//total = 9-2 = 7

Increment operator is just like substraction, but used when you need to substract a numeric value from the variable.

Note – You can also use increment/decrement with mulitiplication, division and modulus operators as well. Try this in the browser.

String Operators

Unlike arithmatic operators, + is the only operator which is used to concatinate 2 or more strings together.

var first = "Fname";
var last = "Lname";
var name = first + " " + last;		//Fname Lname

var first = "Fname";
var name +=" Lname";			//Fname Lname
var name = first + " Lname";		//Fname Lname

String and Numbers

In Javascript you can add numbers and strings together and the output will be a string.

var number = 10;
var name = 'Name';
var result = number+name;	//10name
result = name+number;		//name10

Comparision Operators

Logical Operators

We will go through these operators in more details in the next section when we will cover conditional statements.