var Ann = function a(arr){if(arr.length == 1){return arr;}var rr = new Array();for(var i = 0; i<arr.length;i++){//get a copyvar ar = new Array();for(var j = 0; j < arr.length;j++){ar[j] = arr[j];}//assume ivar current = ar[i];ar.splice(i,1);var childRet = a(ar);for(var k = 0 ;k < childRet.length;k++){rr.push(current + "," + childRet[k]);}}return rr;}var ret = Ann(new Array(1,2,3,4));console.log(ret);