# Handling Numerical Values - Javascript Fundamentals Part 3

Hello, curious student on the internet, today we are going to learn about handling numerical values in Javascript.

In the previous part of fundamentals of Javascript, we covered why `let` is preferred over `var` in Javascript.

Let’s continue our journey to deep dive into the Javascript world from that point.

Declaring integer values
We can declare integer values in JS by using `let` or `const` keyword as shown below:-

``````const radius = 5;
const diameter = 2 * radius;
console.log("The diameter of circle is", diameter);

/*
Output:-
The radius of circle is 5
The diameter of circle is 10
*/
``````

We can also calculate the area of a circle in the above example by using the Math.pow function:-

``````const pi = 3.14;
area = pi * Math.pow(radius, 2);
console.log("The area of circle is", area);

/*
Output:-
The area of circle is 78.5
*/
``````

Negative integers can be declared in a similar way:-

``````let negativeInteger = -1;
console.log("Value of Integer is", negativeInteger);

/*
Output:-
Value of Integer is -1
*/
``````

NaN in Javascript

In javascript, NaN property represents “Not-a-Number” value. This property indicates that a value is not a legal number.
Example for the same could be as shown below using Math.sqrt method:-

``````let negativeInteger = -1;
console.log("Value of Integer is", negativeInteger);
const squareRootOfNegativeInteger = Math.sqrt(negativeInteger);
console.log("Square root of negative integer is", squareRootOfNegativeInteger);

/*
Output:-
Value of Integer is -1
Square root of negative integer is NaN
*/
``````

In the above example, since we tried to calculate square root of a negative integer, the value returned by JS interpreter was NaN.

Cube root

We can calculate cube root of a number using `Math.cbrt` method:-

``````const cubeValue = 125;
const cubeRootValue = Math.cbrt(cubeValue);
console.log("Cube root of",cubeValue,"is", cubeRootValue);

/*
Output:-
Cube root of 125 is 5
*/
``````

Decimal values

Decimal values can be stored using `let` and `const` keywords similar to integers:-

``````const base = 6.3;
const height = 3.9;
const area = (base * height) / 2;
console.log("Area of triangle is",area);

/*
Output:-
Area of triangle is 12.285
*/
``````

Infinity in Javascript

In javascript, `Infinity` is a numeric value that represents positive infinity.

Example:-

``````const integerValue = 3;
const divideByZero = 3/0;
console.log("Value after dividing by Zero", divideByZero);

/*
Output:-
Value after dividing by Zero Infinity
*/
``````

Arithmetic Operations

We can perform addition operation in Javascript using `+` sign:-

``````const firstNumber = 7;
const secondNumber = 8;
const addition = firstNumber + secondNumber;
console.log("The sum of two numbers is",addition);

/*
Output:-
The sum of two numbers is 15
*/
``````

By mistake, if we add a String with an Integer, Javascript will concatenate the numbers instead of adding them as shown below:-

``````const firstNumber = "10";
const secondNumber = 5;
const addition = firstNumber + secondNumber;

/*
Output:-
addition of the two numbers is 105
*/
``````

We can overcome this problem by using parseInt method in Javascript:-

``````const firstNumber = "10";
const secondNumber = 5;
const addition = parseInt(firstNumber) + secondNumber;

/*
Output:-
addition of the two numbers is 15
*/
``````

This is usually required when data received from the server end is in `string` format and we need to convert it to `number` format before using it in our frontend code.

Other arithmetic operations

Subtraction, multiplication and division is carried out using `-`, `*` and `/` sign respectively:-

``````const firstNumber = 3;
const secondNumber = 14;
const difference = firstNumber - secondNumber;
console.log("difference between two numbers is",difference);
const multiplication = firstNumber * secondNumber;
console.log("multiplication of the two numbers is",multiplication);
const division = firstNumber / secondNumber;
console.log("division of the two numbers is",division);

/*
Output:
difference between two numbers is -11
multiplication of the two numbers is 42
division of the two numbers is 0.21428571428571427
*/
``````

We will continue learning more about Javascript language in the upcoming articles in the series.

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See you in my next article, Take care!!