What is the best way to shift a multidimensional array in Javascript? -

i'm trying create javascript function shifts array right x units y units. must keep array size same, , must call unloadchunk elements getting shifted off multidimensional array. here current implementation:

function shift(x, y) {     if (x > 0) {         (var = 0; < chunks.length; i++) {             (var j = chunks[i].length - 1; j >= 0; j--) {                 if(j + x > chunks[i].length - 1 && chunks[i][j]) {                   unloadchunk(i, j);                 }                  if (j < x) {                     chunks[i][j] = null;                 }                 else {                     chunks[i][j] = chunks[i][j - x];                 }             }         }     }     else if (x < 0) {         (var = 0; < chunks.length; i++) {             (var j = 0; j < chunks[i].length; j++) {                 if(j + x  < 0 && chunks[i][j]) {                   unloadchunk(i, j);                 }                  if (j - x >= chunks[i].length) {                     chunks[i][j] = null;                 }                 else {                     chunks[i][j] = chunks[i][j - x];                 }             }         }     }     if (y > 0) {         (var = 0; < chunks.length; i++) {             if (i + y >= chunks.length) {                 (var j = 0; j < chunks.length; j++) {                   if(i - y < 0 && chunks[i][j]) {                     unloadchunk(i, j);                   }                   chunks[i][j] = null;                 }             }             else {                 (var j = 0; j < chunks.length; j++) {                     if(i - y < 0 && chunks[i][j]) {                       unloadchunk(i, j);                     }                     chunks[i][j] = chunks[i + y][j];                 }             }         }     }     else if (y < 0) {         (var = chunks.length - 1; >= 0; i--) {             if (i + y < 0) {                 (var j = 0; j < chunks.length; j++) {                      if(i - y > chunks.length - 1 && chunks[i][j]) {                        unloadchunk(i, j);                      }                     chunks[i][j] = null;                 }             }             else {                 (var j = 0; j < chunks.length; j++) {                      if(i - y > chunks.length - 1 && chunks[i][j]) {                        unloadchunk(i, j);                      }                     chunks[i][j] = chunks[i + y][j];                 }             }         }     } } 

if you're having trouble understanding want shift function do, take @ this fiddle , @ html output. attempt @ creating shift function works, has 10 loops. question was, there more efficient, less verbose way this?

this proposal uses

• array#foreach: visit each item

• array#map: return value each item

• array#pop: removes , return last element

• array#push: adds 1 or more elements @ end

• array#shift: removes , return first element

• array#unshift: adds 1 or more elements @ beginning

for better visibillity, replaced null value 1000, 2000, 3000 , 4000.

function shift(x, y) {      while (x > 0) {          chunks.foreach(function (a) {              a.pop();              a.unshift(1000);          });          x--;      }      while (x < 0) {          chunks.foreach(function (a) {              a.shift();              a.push(2000);          });          x++;      }      while (y > 0) {          chunks.unshift(chunks.pop().map(function () { return 3000; }));          y--;      }      while (y < 0) {          chunks.push(chunks.shift().map(function () { return 4000; }));          y++;      }  }    function print(msg) {      document.body.innerhtml += '<p>' + msg + '</p>';  }    function printarr(arr) {      (var = 0; < arr.length; i++) {          print(json.stringify(arr[i]))      }  }    var chunks = [[5, 3, 1], [9, 2, 5], [2, 3, 7]];    print("chunks: " + json.stringify(chunks));  shift(1, 0);  print("shifting right 1. chunks: "); printarr(chunks);  shift(-1, 0);  print("shifting left 1. chunks: "); printarr(chunks);  shift(0, 1);  print("shifting 1. chunks: "); printarr(chunks);  shift(0, -1);  print("shifting down 1. chunks: "); printarr(chunks);