rest语法|剩余参数|归并参数

// rest语法|剩余参数|归并参数
f = (...arr) => arr;
console.log(f(1, 2, 3, 4, 5, 6, 7, 8, 9));
// ...后面跟集合数据，可以将集合展开        ***********************
console.log(...[1, 2, 3, 4, 5, 6]);

f = (a, b, ...arr) => `${a},${b},"|",${arr}`;
console.log(f(1, 2, 3, 4, 5, 6));
f = (a, b, ...arr) => arr;
console.log(f(1, 2, 3, 4, 5, 6));
f = (a, b, ...arr) => `${arr}`;
console.log(f(1, 2, 3, 4, 5, 6));