reduce 应用例子

记录一下：

let hesuan = {
    hongma: {
        name: '红马',
        child: {
            name: '隔离',
        },
    },
    lvma: {
        name: '绿马',
        pass: {
            name: '通行',
        },
    },
};
let str = 'lvma.pass.name';
let propArr = str.split('.');

let result = propArr.reduce((prev, next) => {
    return prev[next] ? prev[next] : null;
}, hesuan);

console.log(result, '通行');