/*
 *
 * Compute area and circumference
 * 功能：將傳入值作為半徑，計算面積與直徑
 * 
 */
const PI = Math.PI;

//exports.area = (r) => PI * r * r; // 胖箭頭的寫法為以下寫法的精簡版
exports.area = function (r) {
    return PI * r * r;
}

//exports.circumference = (r) => 2 * PI * r; // 胖箭頭的寫法為以下寫法的精簡版
exports.circumference = function (r) {
    return 2 * PI * r;
}