var result=[];        var arr=[1, [2, [ [3, 4], 5], 6]];        function flat(arr,result){            for(var i=0;i<arr.length;i++){                if(typeof arr[i]==="number"){                    result.push(arr[i]);                }                else{                    flat(arr[i],result);                }            }        }        flat(arr,result);        console.log(result);