npm i chain-get -S
import chainGet from 'chain-get';
let person = {age: 12, name: 'huruji', sisters: ['a']}
chainGet(person).age() // 12
chainGet(person).sisters[0]() // a
chainGet(person).sisters[1]() // undefined
chainGet(person).brothers[1]() // undefined
从此告别以下这类代码
if (person && person.sister && persion.sister[0]) {
const sister = person.sister[0]
}