// 无参数 let a = () => {} let a = function () {} // 单个参数 let a = b => {} let a = function (b) {} // 多个参数 let a = (b, c) => {} let a = function (b, c) {} // 不定参数 let a = (b, c, ...args) {} var a = function(b, c, ...args) {}
let F = (...args) => { console.log(args); } F(2,6); // [ 2, 6 ] F(2,4,6); // [ 2, 4, 6 ]
var f = v => v var f = function (v) { return v; }