function sum(x,y,z){
let total = 0;
if(x)total+=x;
if(y)total+=y;
if(z)total+=z;
console.log(`total:${total}`);
}
sum(5,'',9)
function sum2(...m){
let total = 0;
for(var i of m){
total+=i;
}
console.log(`total:${total}`)
}
sum2(4,8,9,10);
let sum3 = (...m)=>{
let total = 0;
for(var i of m){
total+=i;
}
console.log(`total:${total}`);
}
sum3(4,8,9,10);
// var [x,y] = [4,8]
console.log(...[4,8]);
let arr1 = [1,3];let arr2 = [4,8];
console.log("concat: "+arr1.concat(arr2));
console.log([...arr1,...arr2]);
// var [x,y] = [4,8];
var [x,...y] = [4,8,10,30];
let [a,b,c]= 'es6';
let xy = [...'es6'];