js 访问用字符串访问对象中的属性问题

Question

    var obj = {
        a: {
            b： {
                c: 1
            }
        }
    }

想用'a.b.c' 能直接访问到1
怎么写 不是用obj.a.b.c 也不是用obj'a'['c'],
用个函数来转换还是

Answer 1

function getPropByPath(obj, path) {
    let tempObj = obj;
    path = path.replace(/[(w+)]/g, '.$1');
    path = path.replace(/^./, '');

    let keyArr = path.split('.');
    let i = 0;
    for (let len = keyArr.length; i < len - 1; ++i) {
        if (!tempObj) break;
        let key = keyArr[i];
        if (key in tempObj) {
            tempObj = tempObj[key];
        } else {
            return null
            //break;
        }
    }
    return tempObj ? tempObj[keyArr[i]] : null
}

getPropByPath(obj, 'a.b.c') // 1
getPropByPath(obj, 'a[b][c]') // 1