如何使用数组插入多个数据

let arr = [1, 2, 3];
let newData = [4, 5, 6];

for (let i = 0; i < newData.length; i++) {
  arr.push(newData[i]);
}

console.log(arr); // [1, 2, 3, 4, 5, 6]

let arr = [1, 2, 3];
let newData = [4, 5, 6];

let newArr = arr.concat(newData);

console.log(newArr); // [1, 2, 3, 4, 5, 6]

let arr = [1, 2, 3];
let newData = [4, 5, 6];

arr.splice(arr.length, 0, ...newData);

console.log(arr); // [1, 2, 3, 4, 5, 6]