ES6--residual parameters

Seven, remaining parameters (new syntax)

1. The rest parameter syntax allows us to represent an indefinite number of parameters as an array.

function fn(a, b, ...c){console.log(a); //1console.log(b); //2console.log(c); //[3,4,5]}fn(1,2,3,4,5);

For example (to calculate the sum):

//Calculate andconst sum = (...args) => {let total = 0;args.forEach(item => total += item)return total;}console.log(sum(10,20)); //30console.log(sum(10,20,30)); //60

2, rest parameters and destructuring used together

 let stu = ['Xiao Ming','Xiaohong','Xiao Zhang'];let [a1, ...a2] = stu;console.log(a1); //'Xiao Ming'console.log(a2); //['Xiaohong', 'Xiao Zhang']