const arr1 = [1, 2, 3];
const arr2 = [4, 5, 6];
const arr3 = [7, 8, 9];
const mergedArr = [...arr1, ...arr2, ...arr3];
console.log(mergedArr);
// [1, 2, 3, 4, 5, 6, 7, 8, 9]