CodeMirror Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.2.0/codemirror.min.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.2.0/codemirror.min.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.2.0/mode/javascript/javascript.min.js"></script>
<link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap.min.css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.4/js/bootstrap.min.js"></script>
<textarea id= "editor"></textarea>
<br>
<button id = "automatic1">for...in</button>
<button id = "automatic2">for...in that works</button>
<button id = "automatic3">forEach</button>

JavaScript

$(document).ready(function(){
  var editorArea = document.getElementById("editor");
  var editor = CodeMirror.fromTextArea(editorArea, {
      lineNumbers : true
  });

  var array = [];

  var temp = 0;
  for (var i = 0; i<3; i++){
      array[i] = [];
      for (var j = 0; j<3; j++){
          array[i][j] = ++temp + "";
          if (j==2){
              array[i][j+1] = "\n";
          }
      }
  }

  $("#automatic1").click(function(){
      for (var row in array){
          for (var col in array[row]){
              console.log("text: " + array[row][col] + " line: " + row + " ch: " + col);
              console.log(typeof(row));
              editor.replaceRange(array[row][col], {line:row, ch:col});
          }
      }
  });
  
 $("#automatic2").click(function(){
      for (var row in array){
          for (var col in array[row]){
              console.log("text: " + array[row][col] + " line: " + row + " ch: " + col);
              
              var foo = row +1;
              console.log(typeof(foo));
              editor.replaceRange(array[row][col], {line:row+1, ch:col});
          }
      }
  });

  $("#automatic3").click(function(){
    array.forEach(function (item, row) {
        array[row].forEach(function (text, col) {
            console.log("text: " + array[row][col] + " line: " + row + " ch: " + col);
            console.log(typeof(row));
            editor.replaceRange(text, {line:row, ch:col});
        })
    })
  });


// just for kicks
  /*$("#automatic2").click(function(){
      for (var i = 0; i<array.length; i++){
          for (var j = 0; j<array[i].length; j++){
              editor.replaceRange(this.array[i][j], {line:i, ch:j});
          }
      }
  });*/
});