Accumulation items in a table Options

[denmarks]

I have a table where one of the columns is activities. That field can contain any letters of the alphabet. There can be no duplicates within a cell but there can be none or any. There is a blank between each letter for readability. For example:
A C D F G
A B
[blank]
M N O R Z

What is the best way to scan the table and count how many of each letter appears? I assume creating an array and indexing by the letter may work best for the variables. I also need the best way to scan the table and the individual cell that would be compatible with multiple browsers.
Result
A - 2
B - 1
C - 1
etc

[denmarks]

This a table that I create but I constantly change. I wanted an automated way to count the letters.
This is for a group going on a cruise.
A - means they will attend event XXX
B - means they will attend event YYY
C - means they will attend event ZZZ

See http://hawaii.dmmarks.com

I want an automated way to count the number of people attending each event. Right now I manually count them and since changes are made often I sometimes make a mistake.

I did find one method but it worked in Firefox and not in IE. Also the counting of the letters in a cell was too slow.

[Christian J]

I want an automated way to count the number of people attending each event. Right now I manually count them and since changes are made often I sometimes make a mistake.

It's relatively easy to find an occurence of say letter A in a cell, and then add up all such occurences. Duplicates can then be excluded from the count (that is, multiple A letters in a cell still just count as one).

Do you also want to remove duplicates in each cell for "esthetic" reasons? That's more tricky (=bug prone), especially if there are linebreaks etc in the code.

[denmarks]

I want an automated way to count the number of people attending each event. Right now I manually count them and since changes are made often I sometimes make a mistake.

It's relatively easy to find an occurence of say letter A in a cell, and then add up all such occurences. Duplicates can then be excluded from the count (that is, multiple A letters in a cell still just count as one).

Do you also want to remove duplicates in each cell for "esthetic" reasons? That's more tricky (=bug prone), especially if there are linebreaks etc in the code.

There will never be duplicates since I an entering the letters. There are no forced line breaks. There is a space between each letter.

I need to do 2 things. I need a way to do a loop through the cells that will work for any browser. The contents of a cell will then be assigned to a variable. This is where I had a problem of it working for Firefox and not IE. I have found routines that will accumulate numbers in the cells and I tried to alter one of them. The problem occurred when trying to place the contents of the cell into a variable. It worked in Firefox but was null in IE. Sorry I did not keep the code.

Now I need the best way to accumulate the count of each letter. I do not want to create 26 if statements. There must be a more esoteric way to do a scan of the variable and for each letter add one to its corresponding accumulator. I believe that arrays can be indexed by a name (letter) rather than occurrence number. My first try was with 26 if statements and 26 variables. This is too much code. There must be an easier way.

Note that I do this for fun and as a learning experience, not because it must be done. Obviously I can continue to do the count manually. I only want to program it if it can be done with a relatively short routine.

Once I have the accumulation I have no problem putting it on the page. I do it with date counts now.

This post has been edited by denmarks: May 29 2012, 01:53 PM

[Christian J]

There will never be duplicates since I an entering the letters. There are no forced line breaks. There is a space between each letter.

Then I misunderstood everything, I thought you wanted a kind of validation script to catch typos. Counting correct cell content is much easier.

I believe that arrays can be indexed by a name (letter) rather than occurrence number.

That's called an associative array. Here's an example that seems to work in my browsers:

CODE

<table border=1 id="memberTable">
<tr>
<th>foo</th>
<th>bar</th>
</tr>
<tr>
<td>text</td>
<td>A B C</td>
</tr>
<tr>
<td>text</td>
<td>B A</td>
</tr>
<tr>
<td>text</td>
<td>B</td>
</tr>
<tr>
<td>text</td>
<td></td>
</tr>
</table>

<p id="totals"></p>

<script type="text/javascript">
var cruise_events={'A':0, 'B':0, 'C':0}; // default values are zero for each cruise event

var table=document.getElementById('memberTable');
var totals=document.getElementById('totals');

for(var letter_item in cruise_events)
{
    var num=0; // tally
    for(var i=1; i<table.rows.length; i++)
    {
        // get cell content of last cell in row
        var row_cells=table.rows[i].cells;
        var last_cell=row_cells[row_cells.length-1];
        var cell_content=last_cell.innerHTML;

        // tally of each cruise event
        if(cell_content.indexOf(letter_item)!=-1)
        {
            num++;
        }
    }
    cruise_events[letter_item]=num;
}

// display results
for(var letter_item in cruise_events)
{
    totals.innerHTML+=letter_item+': '+cruise_events[letter_item]+'<br>';
}
</script>

[denmarks]

There will never be duplicates since I an entering the letters. There are no forced line breaks. There is a space between each letter.

Then I misunderstood everything, I thought you wanted a kind of validation script to catch typos. Counting correct cell content is much easier.

I believe that arrays can be indexed by a name (letter) rather than occurrence number.

That's called an associative array. Here's an example that seems to work in my browsers:

CODE

<table border=1 id="memberTable">
<tr>
<th>foo</th>
<th>bar</th>
</tr>
<tr>
<td>text</td>
<td>A B C</td>
</tr>
<tr>
<td>text</td>
<td>B A</td>
</tr>
<tr>
<td>text</td>
<td>B</td>
</tr>
<tr>
<td>text</td>
<td></td>
</tr>
</table>

<p id="totals"></p>

<script type="text/javascript">
var cruise_events={'A':0, 'B':0, 'C':0}; // default values are zero for each cruise event

var table=document.getElementById('memberTable');
var totals=document.getElementById('totals');

for(var letter_item in cruise_events)
{
    var num=0; // tally
    for(var i=1; i<table.rows.length; i++)
    {
        // get cell content of last cell in row
        var row_cells=table.rows[i].cells;
        var last_cell=row_cells[row_cells.length-1];
        var cell_content=last_cell.innerHTML;

        // tally of each cruise event
        if(cell_content.indexOf(letter_item)!=-1)
        {
            num++;
        }
    }
    cruise_events[letter_item]=num;
}

// display results
for(var letter_item in cruise_events)
{
    totals.innerHTML+=letter_item+': '+cruise_events[letter_item]+'<br>';
}
</script>

THANKS