求star

①ES6扩展运算...#

let arr1 = [1,3,5],
    arr2 = [2,4,6]
let newArr = [...arr1,...arr2]

②遍历添加#

let arr1 = [1,3,5],
    arr2 = [2,4,6]
// forEach、map、filter、every、for、for in、for of等等
arr1.forEach(item => {
    arr2.push(item)
})

③concat方法#

let arr1 = [1,3,5],
    arr2 = [2,4,6]
arr1.concat(arr2)

④splice方法#

let arr1 = [1,3,5],
    arr2 = [2,4,6]
arr1.splice(arr.length, 0, ...arr2)