demo/ES6.html

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width,initial-scale=1.0">
    <title>ES6</title>
  </head>
  <body>
      <h2>ES6 demo</h2>
      <script>
         /* ES5 */
         function sum(x, y, z){
          let total = 0;
          if(x) total += x;
          if(y) total += y;
          if(z) total += z;
          console.log(`total:${total}`)
         }
         sum(5, '', 9);


         /* ES6 */
         function sum2(...args){ // Rest参数
            let total = 0;
            for(var i of args){
              total += i;
            }
            console.log(`total:${total}`)
         }
         sum2(4, 8, 10);

         /* ES6 */
        let sum3 = (...args) => {  // Rest参数 + 箭头函数
          let total = 0;
          for(var i of args){
            total += i;
          }
          console.log(`total:${total}`)
        }
        sum3(4, 8, 8);

        var [x, y] = [4, 8];   // 解构赋值
        console.log(...[4,8]);  // 这里的...是数组扩展

        let arr1 = [1,3]
        let arr2 = [4, 8];
        console.log("concat:" + arr1.concat(arr2));
        console.log([...arr1, ...arr2]); // 这里的...是数组扩展

        var [x, ...y] = [4, 8, 10, 30];  // Rest + 解构赋值
        console.log(x, y);

        let [a, b, c] = 'ES6';  // 字符串的解构
        console.log(a, b, c);

        let xy = [...'ES6'];  // 数组的扩展
        console.log(xy);

      </script>
  </body>
</html>