function arrCopy(arr, offset) {
	    offset = offset || 0;
	    var len = Math.max(0, arr.length - offset);
	    var newArr = new Array(len);
	    for (var ii = 0; ii < len; ii++) {
	      newArr[ii] = arr[ii + offset];
	    }
	    return newArr;
	  }
function arrCopy(arr, offset) {
	    offset = offset || 0;
	    var len = Math.max(0, arr.length - offset);
	    var newArr = new Array(len);
	    for (var ii = 0; ii < len; ii++) {
	      newArr[ii] = arr[ii + offset];
	    }
	    return newArr;
	  }
function arrCopy ( arr , offset ) { offset = offset || 0 ; var len = Math . max ( 0 , arr . length - offset ) ; var newArr = new Array ( len ) ; for ( var ii = 0 ; ii < len ; ii ++ ) { newArr [ ii ] = arr [ ii + offset ] ; } return newArr ; }
http://jsperf.com/copy-array-inline
http : // jsperf . com / copy - array - inline