In this **Day 1: Let and Const 10 days of javascript** problem you need to Declare a constant variable, PI, 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). Read a number, r, denoting the radius of a circle from stdin. Use PI and r to calculate the area and perimeter of a circle having radius r. The print area as the first line of output and the print perimeter is the second line of output.

# HackerRank Day 1: Let and Const 10 days of javascript problem solution.

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

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