JavaScript 展开运算

展开运算

//数组展开
<script>
let arr1 = [1, 2, 3, 4];
let arr2 = [5, 6, 7, 8];
let newarr = [...arr1, ...arr2];
console.log(newarr) //[1, 2, 3, 4, 5, 6, 7, 8]
</script>

//二维数组展开
<script>
let uname = {name: 'zs'};
let age = {age: 30};
let stu = {...uname,...age};
console.log(stu);//{name: "zs", age: 30}
</script>

小练习1

<script>
function max(arr) {
     return Math.max(...arr);
}
console.log(max([1, 2, 3, 4]));
</script>

小练习2

function fn2(num1, ...num2) {
     console.log(num1, num2);
}
fn2(10, 20, 30, 40);//10 [20, 30, 40]