I am trying to use 2 dimensional array in javascript for storing strings. But I am not able to get the values correctly. Below is my code.

      var mentstore=new Array();
        function creating(id,day)
        {
            if(mentstore[day,id] != null)
         {
             alert("It already exists: mentstore["+day+"]["+id+"]"+mentstore[day,id] );
             var textinput="<div id='closeit'>Comments:<input type='text' name='m["+day+"]  ["+id+"]' value='"+mentstore[day,id]+"'/></div>
                               <div id='closing' onclick='closement("+id+","+day+")'>:)</div>";
         }
            else
            {
                var textinput="<div id='closeit'>Comments:<input type='text' name='m["+day+"]  ["+id+"]' /></div>
                               <div id='closing' onclick='closement("+id+","+day+")'>:)</div>";  
                $('#m').html(textinput);
            }

    function closement(id,day)
    {
        m.style.visibility='hidden';
        var str='m['+day+']['+id+']';
        var element = document.getElementById(str);
     if(element.value !=null)
     {
      mentstore[day,id]=element.value;
      alert('New values stored: mentstore['+day+']['+id+']'+mentstore[day,id]);
     }
    }

So in the above code if mentstore[0,0]='man' then mentstore[1,0] and [2,0] and [3,0] ....[7,0] are also filled with 'man'. Same thing is happening with mentstore[0,1] even mentstore[4,1] scenarios. Can any one please provide any tutorial or sample code where we can dynamically create javascript 2d arrays. Thanks in advance.

I am trying to use 2 dimensional array in javascript for storing strings. But I am not able to get the values correctly. Below is my code.

      var mentstore=new Array();
        function creating(id,day)
        {
            if(mentstore[day,id] != null)
         {
             alert("It already exists: mentstore["+day+"]["+id+"]"+mentstore[day,id] );
             var textinput="<div id='closeit'>Comments:<input type='text' name='m["+day+"]  ["+id+"]' value='"+mentstore[day,id]+"'/></div>
                               <div id='closing' onclick='closement("+id+","+day+")'>:)</div>";
         }
            else
            {
                var textinput="<div id='closeit'>Comments:<input type='text' name='m["+day+"]  ["+id+"]' /></div>
                               <div id='closing' onclick='closement("+id+","+day+")'>:)</div>";  
                $('#m').html(textinput);
            }

    function closement(id,day)
    {
        m.style.visibility='hidden';
        var str='m['+day+']['+id+']';
        var element = document.getElementById(str);
     if(element.value !=null)
     {
      mentstore[day,id]=element.value;
      alert('New values stored: mentstore['+day+']['+id+']'+mentstore[day,id]);
     }
    }

So in the above code if mentstore[0,0]='man' then mentstore[1,0] and [2,0] and [3,0] ....[7,0] are also filled with 'man'. Same thing is happening with mentstore[0,1] even mentstore[4,1] scenarios. Can any one please provide any tutorial or sample code where we can dynamically create javascript 2d arrays. Thanks in advance.

• javascript
• dynamic
• multidimensional-array

• [day,id] is equivalent to just doing [id] – Eli Grey Commented Dec 28, 2009 at 15:45
• Thank you all for helping. It is now working fine. I need to verify it more. Thanks again.. – Enjoy coding Commented Dec 28, 2009 at 15:58

3 Answers 3

Replace mentstore[day,id] with mentstore[day][id]. That's the syntax for multi-dimensional arrays.

Use mentstore[0][0] instead of mentstore[0,0]. Also, use strict paraison whenever loose paraison is not needed:

var mentstore = [];

function creating(id,day)
{
    if(mentstore[day] === undefined) mentstore[day] = [];
    if(mentstore[day][id] !== undefined)
    {
        alert("It already exists: mentstore["+day+"]["+id+"]"+mentstore[day][id] );
        var textinput="<div id='closeit'>Comments:<input type='text' name='m["+day+"]  ["+id+"]' value='"+mentstore[day][id]+"'/></div>
                       <div id='closing' onclick='closement("+id+","+day+")'>:)</div>";
    }
    else
    {
        var textinput="<div id='closeit'>Comments:<input type='text' name='m["+day+"]  ["+id+"]' /></div>
                       <div id='closing' onclick='closement("+id+","+day+")'>:)</div>";  
        $('#m').html(textinput);
    }

function closement(id,day)
{
    m.style.visibility='hidden';
    var element = document.getElementById(str);
    if(element.value !== '')
    {
        mentstore[day][id]=element.value;
        alert('New values stored: mentstore['+day+']['+id+']'+mentstore[day][id]);
    }
}

edit: in the original code, str is undefined and the execution fails. You can fix it in closement with:

var element = $('#closeit > input').eq(0);

JavaScript only supports arrays with a single index but the index can be anything, so if you really want two dimensional arrays, do this:

mentstore[day+','+id] = ...

i.e. use a string with to ponents as the key.