﻿ Operators in JavaScript with Examples

# Operators in JavaScript with Examples

Operators in JavaScript are used to perform various mathematical and logical comparisons on data values or operands, to produce a result.

For example,

5 + 7 = 12

The + (plus sign) here, is an operator (an arithmetic operator), the number 5 is the left operand and the value 7 is the right operand.

In JavaScript, you can assign the data values (or the operands) to variables and apply an operator to get a result, or you can simply use numbers along with an operator and get the result. For example,

```<script>
var a = 5;
var b = 7;
var c = a + b;

// Using ES6 features.
// let a = 5;
// let b = 7;
// let c = a + b;
</script>```

Or, simply use numbers with the + operator.

```var result = 5 + 7;

// Using ES6 features.
// let result = 5 + 7;
// alert (result);	    // its 12 again.```

Note: The + operator can also be used to concatenate (or add) strings. I have explained about it here.

Its basic math and we have done this before. Therefore, lets begin with the Arithmetic Operators.

## JavaScript Arithmetic Operators

Table created using HTML Table Generator
Operator Description
- Subtraction
* Multiplication
/ Division
% Modulus (gives the remainder obtained by dividing two operands or numbers)
More examples using modulus operator
++ Increment (It will increase value by 1)
-- Decrement (it will decrease the value by 1)

## Using + Operator to Concatenate Values

The + (plus) operator is often used to add two or more numbers. However, it can also be used to concatenate two values of different data types. For example,

var name = 'alpha';
var age = 27;
alert (name + ' is ' + age + ' years old');

// Using ES6
let name = 'alpha';
let age = 27;
alert (name + ' is ' + age + ' years old');

We can use the + on different data types to get different results. For example,

```// Concatenating two string values.
let a = 'arun ', b = 'banik';
alert (a + b);	 // the result is arun banik

// or

// Concatenating a string with number.
let x = 3, y = ' dimension';
alert (x + y); 	    // the result is 3 dimension.```

Interesting isn't?

Note: Be careful while using the + operator. The results can vary.
Can you spot the difference between the two examples below?

```1)
let a, b;
a = 5;
b = 7;
document.getElementById('result').innerHTML = 'a + b ' + ' = ' + (a + b);

2)
let a, b;
a = 5;
b = 7;
document.getElementById('result').innerHTML = 'a + b ' + ' = ' + a + b;```

Ok, let’s move on to the next set of operators.

## JavaScript Comparison Operators

Comparison operators in JavaScript are used to compare two given values, and the result is returned in a Boolean value, that is, true or false.

Table created using HTML Table Generator
Operator Description
== equal to Try it
=== compares equal value with equal type Try it
!= not equal (compares two operands that are not equal) Try it
> greater than Try it
< less than Try it
>= greater than or equal to Try it
<= less than or equal to Try it

## JavaScript Conditional Operator

JavaScript also has a conditional operator called the ternary operator. It assigns a value to a varible after satisfying a conditon. Its actually works like the if...else statement. I have explained about ternary operator in detail here.

### Syntax

Condition ? first_expression : second_expression

## JavaScript Logical Operators

The logical operators are used to compare two or more conditions.

Operator Description
&& the logical AND operator Try it
|| the logical OR operator Try it
! the logical NOT operator Try it

## JavaScript Assignment Operators

Assignment operators in JavaScript are used to assign values to variables. For example,

let a = 5;

Here, I have assigned the value 5 to the variable a using the = (or, equal assignment) operator. It can also be a = b, assigning value to a variable from another variable. There are many more assignment operators like this.

Operator Description
= Assign right operand value to the left operand. For example,
a = 5;
or
a = b;
Don’t get confused with "=" to "==" (see Comparison Operators)
Try it
+= Sum of two right operand values is assigned to the left operand. For example,
a = a + b;
or
a += b;
Try it
-= Subtract right operand value from the left operand and assign the result to the left operand. For example,
a -= 2;
or
a = a – 2;
Try it
*= Multiply right and left operand values and assign the result to the left operand. For example,
a *= 5;
or
a = a * 5;
or
a = a * b;
Try it
/= Divide left operand value with the right operand and assign the result to the left operand. For example,
a /= 5;
or
a = a / 5;
or
a = a / b;
Try it
%= Get the modulus of left operand, divide it by right operand and assign the result to the left operand. For example,
a %= 2;
or
a %= b;
or
a = a % b;
See more examples
Try it