【力扣JavaScript】71. 简化路径

/**
 * @param {string} path
 * @return {string}
 */
var simplifyPath = function(path) {
    let stack=[];
    let str='';
    let arr=path.split('/');
    arr.forEach(
        val=>{
            if(val&&val=='..'){
                stack.pop();
            }else if(val&&val!='.'){
                stack.push(val);
            }
        }
    )
    arr.length?str='/'+stack.join('/'):str='/';
    return str;
};