sum of reduce

by s_hiroshi

HTML

<div id="result1"></div>
<div id="result2"></div>

JavaScript

/*
 * Array.prototype.reduce()で合計を計算
 */
const numbers = [1,2,3,4,5,6,7,8,9,10];
total = numbers.reduce((prev, current) => prev + current, 0);

document.querySelector('#result1').innerHTML = total; // 55


/*
 * Array.prototype.filter()で偶数を抽出
 */
 const even = numbers.filter(n => n % 2 === 0);
 let content = '';
 for (let n of even) {
     content += n;
 }
 
 document.querySelector('#result2').innerHTML = content; // 246810