let and const || JS Hackerrank Solution

 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

 

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()'.     const PI=Math.PI;   var  r=readLine();     let area=PI*(r*r)     console.log(area);     let perimeter=2*PI*r;     console.log(perimeter);     // Print the area of the circle:          // Print the perimeter of the circle:       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.");     }   }