编辑代码

const resolve = (paths) => {
    if (!(Array.isArray(paths) && paths.length > 0)) return ''

    let result = paths.reduce((pre, curr) => {
        if (typeof curr === 'string') {
            let start = 0, end = curr.length;

            if (curr[0] === '/') ++start;
            if (curr[end - 1] === '/') --end;

            curr = curr.slice(start, end)
            return pre + curr + '/';
        }

        return pre;

    }, '/')

    return result;
}

console.log(resolve(['/base/a', undefined, '/page/index/index/']))