Day 1: Let and Const

Let and Const || Hackerrank Solution 

Objective

In this challenge, we practice declaring variables using the let and const keywords. Check out the attached tutorial for more details.

Task

1. Declare a constant variable, , and assign it the value Math.PI. You will not pass this challenge unless the variable is declared as a constant and named PI (uppercase).
2. Read a number, , denoting the radius of a circle from stdin.
3. Use  and  to calculate the  and  of a circle having radius .
4. Print  as the first line of output and print  as the second line of output.

Input Format

A single integer, , denoting the radius of a circle.

Constraints

•  is a floating-point number scaled to at most  decimal places.

Output Format

Print the following two lines:

1. On the first line, print the  of the circle having radius .
2. On the second line, print the  of the circle having radius .

Sample Input 0

2.6

Sample Output 0

21.237166338267002
16.336281798666924

Explanation 0

Given the radius , we calculate the following:

We then print  as our first line of output and  as our second line of output.

Solution:

function main() {
    // Write your code here. Read input using 'readLine()' and print output using 'console.log()'.
    const PI=Math.PI;
    let r = parseFloat(readLine());
    // Print the area of the circle:
    let area = PI*r*r;
    console.log(area);
    // Print the perimeter of the circle:
    let perimeter= 2*PI*r;
    console.log(perimeter);