concat

const a = [1]
const b = [2]
const result = a.concat(b) // [1, 2]

apply

const a = [1]
const b = [2]
Array.prototype.push.apply(a, b)
console.log(a) // [1,2]

去重

const a = [{ id: 1135 }, { id: 1136 }]
const b = [{ id: 1135 }, { id: 1136 }, { id: 1138 }]
const all = a.concat(b)
const map = new Map()
for (const item of all) {
    if (!map.has(item.id)) {
        map.set(item.id, item)
    }
}
console.log([...map.values()])