Hackerrank | 10 Days of Javascript | Day 1-Solution in JS | Let-and-Const-hackerrank-Solution-in-JS

Hackerrank | 10 Days of Javascript | Day 1-Solution in JS | Let-and-Const-hackerrank-Solution-in-JS

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.

https://www.hackerrank.com/challenges/js10-let-and-const/problem

Day 1: Let and Const Solution in JS

'use strict';

process.stdin.resume();
process.stdin.setEncoding('utf-8');

let inputString = '';
let currentLine = 0;

process.stdin.on('data', inputStdin => {
    inputString += inputStdin;
});

process.stdin.on('end', _ => {
    inputString = inputString.trim().split('\n').map(string => {
        return string.trim();
    });
    
    main();    
});

function readLine() {
    return inputString[currentLine++];
}

function main() {
    let s = readLine();
    console.log(Math.PI * s * s);
    console.log(Math.PI * 2 * s);
    try {    
        // Attempt to redefine the value of constant variable PI
        PI = 0;
        // Attempt to print the value of PI
        console.log(PI);
    } catch(error) {
        console.error("You correctly declared 'PI' as a constant.");
    }
}