CODEWITHSUNDEEP
phpmysqlarrays
Steven Matthews
Steven Matthews

Reputation: 11285

Pulling out array elements

So I am print_r-ing an array, generated as follows:

while ($twitgroup = mysql_fetch_array($resulttwitter)) {
print_r($twitgroup);
}

I get this output (with multiple more arrays, dependent on rows).

Array ( [0] => composed [category] => composed [1] => 330 [value] => 330 [2] => 1344384476.94 [timestamp] => 1344384476.94 ) Array ( [0] => elated [category] => elated [1] => 2034 [value] => 2034 [2] => 1344384476.94 [timestamp] => 1344384476.94 ) Array ( [0] => unsure [category] => unsure [1] => 2868 [value] => 2868 [2] => 1344384476.94 [timestamp] => 1344384476.94 ) Array ( [0] => clearheaded [category] => clearheaded [1] => 1008 [value] => 1008 [2] => 1344384476.94 [timestamp] => 1344384476.94 ) Array ( [0] => tired [category] => tired [1] => 2022 [value] => 2022 [2] => 1344384476.94 [timestamp] => 1344384476.94 )

I want to be able to pull individual values here, but I'm having trouble. I'm trying to use a while loop on these arrays, but I think maybe that's wrong. Should I perhaps use a foreach loop, and then on the output of that foreach, access each element of the array?

Say for example, I want to grab composed, and the value of composed. How would I do that?

I'm pretty good with arrays/lists in Python, but my experience with arrays in PHP is somewhat lacking.

Upvotes: 2

Views: 1151

Answers (4)

Ярослав Рахматуллин
Ярослав Рахматуллин

Reputation: 7922

This is what you have:

  Array ( 
    [0]         => composed 
    [category]  => composed 
    [1]         => 330  
    [value]     => 330 
    [2]         => 1344384476.94 
    [timestamp] => 1344384476.94 
) Array (
    [] =>
    [] =>
    ...
) ...

Arrays in PHP are called associative arrays because they can have either keys out of integers, strings or anything else. You have an array with arrays in it.

To access the individual fields, it would be most convenient to use a for each loop.

$record=0;
foreach ($array as $k => $subArray) {
    $record++;
    foreach($subArray as $field => $value) {
        printf("%d: %s = %s\n", $record, $field, $value);
    }
}

Its seems to me that there is something wrong with the way you are fetching the data, becasue half the fields seem redundant. You can use the string keys to figure out the contents. so there is no need for the n => name entries.

If that can't be helped, I guess you could iterate over the values with 

$ix=0;
for ($i=0; $i < (count($array)/2); $i++){
   printf("%s\n", $array[$ix]);
   $ix++;
}

Upvotes: 0

air4x
air4x

Reputation: 5683

Use 

while ($row = mysql_fetch_assoc($resulttwitter)) {
  $twitgroup[$row['category']] = $row;
}

echo $twitgroup['composed']['value'];     // outputs 330 
echo $twitgroup['composed']['timestamp']; // outputs 1344384476.94

If you only want categories and their values use

while ($row = mysql_fetch_assoc($resulttwitter)) {
  $twitgroup[$row['category']] = $row['value'];
}

echo $twitgroup['composed'];     // outputs 330

Upvotes: 1

janenz00
janenz00

Reputation: 3310

mysql_fetch_array includes each field twice in the result, one associated with a numeric key and one with the field name.

That is why you have 

   [0] => composed 
   [category] => composed
   [1] => 330 
   [value] => 330

You can access field either like :

  $twitgroup[0]

or like :

  $twitgroup['category']

So, you can access your each row like : 

  while ($twitgroup = mysql_fetch_array($resulttwitter)) {
          print $twitgroup['category']; // or print $twitgroup['0'];
          print $twitgroup['value']; // // or print $twitgroup['1'];

          // or by the corresponding numeric indices.

   }

If at all you want to limit your result to either numeric or Associative array, add an additional flag (result_type) to your mysql_fetch_array :

   mysql_fetch_array ($resulttwitter, MYSQL_ASSOC) // or mysql_fetch_array ($resulttwitter, MYSQL_NUM)

Having said all this, it is highly discouraged using mysql_* functions in PHP since they are deprecated. You should use either mysqli or PDO instead.

Upvotes: 0

Geoff Montee
Geoff Montee

Reputation: 2597

Replace mysql_fetch_array with mysql_fetch_assoc to eliminate duplicates. Then this:

while ($twitgroup = mysql_fetch_assoc($resulttwitter)) 
{
    foreach ($twitgroup as $key => $value)
    {
        echo "$key => $value\n";
    }
}

You could also get the elements by name:

while ($twitgroup = mysql_fetch_assoc($resulttwitter)) 
{
    echo "category => " . $twitgroup["category"] . "\n";
    echo "value => " . $twitgroup["value"] . "\n";
    echo "timestamp => " . $twitgroup["timestamp"] . "\n";
}

Upvotes: 0

Related Questions