[RESOLVED] How to add a dimension to an array?

timski72

I have an array ($words) which contains several words in it, e.g.
$words[1] this
$words[2] is
$words[3] a
$words[4] test

This array was created by extracting words from a list of words separated by commas using explode().

During a later function I'd like to add an extract dimension (not sure if that is the correct terminology) that indicates whether the word is a new word or not, .e.g.

$words[1] this, Y
$words[2] is, N
$words[3] a, Y
$words[4] test, N

What would be the best way of going about this? Can you add an extra dimension once you already have an array, or should you define the array first?

Thanks,
Tim.

NogDog

If the words will be unique, you have two choices, if not, then 1.

The choice that works in either case is to add a dimension, which might be something like:

$words[] = array('word' => 'this', 'new' => 'Y');
$words[] = array('word' => 'is', 'new' => 'N');

Then you would access the values as $words[0]['word'] or $words[1]['new'], for example.

If the words will be unique, then you could use them as an associative array key and keep it at just one dimension (the values would be the Y/N to indicate newness):

$words['this'] = 'Y';
$words['is'] = 'N';

I'd likely go with the first, multi-dimension choice as it is more flexible and scalable, plus you don't have to worry about whether any of the words might happen to have some invalid character that cannot be used as an array key.

timski72

Thanks NogDog,

I tested this out and my array seems to be building ok but I'm having trouble accessing the values in it.

I built my array in a loop as follows:

$testWords[$testWordCount++]=array("word"=>$resultWord, "new"=>"Y", "sequence"=>++$Sequence);

The contents of the array are as in the attachment.

Later I try to build a table in a loop and reference the array as follows:

<tr>
<td><div align=\"center\">$testWords[$i]['sequence']</div></td>
<td><div align=\"center\">$testWords[$i]['word']</div></td>
</tr>

This doesn't work as expected. In the table where I expected to see the word sequence, e.g. 1, I get "Array['sequence']" and so on.

Clearly I've made a mistake in the way I am referencing the array but I'm not sure what.
Thanks,
Tim.

dagon

can you show us what $testWords looks like

print_r($testWords);

timski72

Hi Dagon,

Here is the content of the array.

Array ( [0] => Array ( [word] => this [newword] => N [sequence] => 1 ) [1] => Array ( [word] => is [newword] => N [sequence] => 2 ) [2] => Array ( [word] => a [newword] => Y [sequence] => 3 ) [3] => Array ( [word] => test [newword] => Y [sequence] => 4 ) )

In the loop where I am drawing the table the iterated array has the values I want too.

Here is the code for the table.

 
for ($i = 0; $i <= $totalNoWords -1; $i++) {

$Sequence = $i + 1;

echo 	"<tr>
      	<td><div align=\"center\">$testWords[$i][sequence]</div></td>
		<td><div align=\"center\">$testWords[$i][word]</div></td>
	</tr>\n";
}

Instead of the table cells containing the content of the array they contain the following:

Array[sequence] Array[word]

Thanks,
Tim.

dagon

its the echo, try this

echo     '<tr>
              <td><div align="center">'.$testWords[$i]['sequence'].'</div></td>
            <td><div align="center">'.$testWords[$i]['word'].'</div></td>
        </tr>';

timski72

Thanks Dagon,

That worked.

Do you mind if I ask why the dots are required? I thought that was when you wanted to concatenate variables?

Thanks,
Tim.

bradgrafelman

timski72;10966110 wrote:
Do you mind if I ask why the dots are required? I thought that was when you wanted to concatenate variables?

First, they aren't required - there is an alternative way of doing it (i.e. using the "complex syntax" and wrapping the array reference in curly braces inside of the double-quote delimited string). However, many prefer to break out of the string and concatenate the array reference outside of the quotes - it often looks cleaner and is easier to read.

Second, the period is indeed the concatenation operator. However, you don't concatenate variables, you concatenate strings (it's one of the fundamental operations you can do with two strings - join them together).

For more information on the array issue, see this section in the PHP manual.

dagon

echo     "<tr>
              <td><div align=\"center\">{$testWords[$i]['sequence']}</div></td>
            <td><div align=\"center\">{$testWords[$i]['word']}</div></td>
        </tr>";

works also, but think is ugly harder to maintain, and having to escape the html elements is a pain.

NogDog

dagon;10966127 wrote:
echo     "<tr>
              <td><div align=\"center\">{$testWords[$i]['sequence']}</div></td>
            <td><div align=\"center\">{$testWords[$i]['word']}</div></td>
        </tr>"; 
works also, but think is ugly harder to maintain, and having to escape the html elements is a pain.

It is perfectly legal to use single quotes for [X]HTML attributes, so that you do not have to escape them. And then there's HEREDOC, and printf() for other options. (As the Perl community likes to say, "There's more than one way to do it." 🙂

// double-quoted with internal single quotes and complex variable notation:
echo "   <tr>
      <td style='text-align: center'>{$testWords[$i]['sequence']}</td>
      <td style='text-align: center'>{$testWords[$i]['word']}</td>
   </tr>
";

// HEREDOC string literal with complex variable notation:
echo <<<EOD
   <tr>
      <td style="text-align: center">{$testWords[$i]["sequence"]}</td>
      <td style="text-align: center">{$testWords[$i]["word"]}</td>
   </tr>
EOD;

// printf(), and introducing htmlentities() (which could also be used with concatenation):
printf(
   '   <tr>
      <td><div align="center">%s</td>
      <td><div align="center">%s</td>
   </tr>',
   htmlentities($testWords[$i]["sequence"]),
   htmlentities($testWords[$i]["word"])
);

PS: I got rid of the unneeded <div> tags and used a style attribute on the <td>, just to get rid of redundant mark-up (and the deprecated "align" attribute).

NogDog

Oh, and don't forget the ever-popular switching in and out of PHP mode: 🙂

   <tr>
      <td style='text-align: center'><?php echo $testWords[$i]['sequence'];?></td>
      <td style='text-align: center'><?php echo $testWords[$i]['word'];?></td>
   </tr>

<!-- using htmlentities() -->
   <tr>
      <td style='text-align: center'><?php
      echo htmlentities($testWords[$i]['sequence']);?></td>
      <td style='text-align: center'><?php
      echo htmlentities($testWords[$i]['word']);?></td>
   </tr>

timski72

Thanks NogDog! There are many ways to skin a cat I see :-)