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I have a while loop that uses the fgetcsv function and iterates through a csv file until the end. In the loop I want to add a value from a specific column to a new array.

Everything works as it echos the value from the column that I need. However when I put the line in to add to the array it does not work. I have a HTML table that prints after the PHP code however when I use the line to add to the array it does not work.

I have looked on the internet and everything I have seen is doing it the way I have done so I am a little confused.

Here is my code:

$amountRecords = 0;
$totalValue = 0;
$valueArray = array();

$handle = fopen('data.csv', 'r');
// to skip the header names/values 
fgetcsv($handle);

while($row = fgetcsv($handle, "\r"))
{

    $valueArray[$amountRecords] += $row[1]; // THIS IS THE LINE THAT IS NOT WORKING
    $totalValue = $totalValue + $row[1];
    $amountRecords++;

}
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2 Answers

up vote 2 down vote

There is some strangeness with your code. You're incrementing $amountRecords each time, so you'll never access the same index in $valueArray twice, yet, you're adding values to each element. Possibly you simply mean to assign the value with $valueArray[$amountRecords] = $row[1]; instead of +=?

If that's the case, it looks like you're simply attempting to add the item onto the end of the array, extracting column 1 into its own array. You should use array_push or array[]= syntax for that:

while($row = fgetcsv($handle, "\r"))
{
    // Add $row[1] to the end of $valueArray
    $valueArray[] = $row[1];

    $totalValue = $totalValue + $row[1];
}

The += operator is for adding something to an existing value. Typing a += b is the same as typing a = a + b. You should be using that operator on the next line, for example:

 $totalValue += $row[1];

As a final suggestion, learn to do some basic debugging. If your loop isn't working, make it show you what it's doing during each iteration. Use var_dump to inspect your variables and make sure they actually contain what you think they contain. Using var_dump($row) would be especially useful in making sure that $row[1] is the correct index.

echo "Before loop\n";

while($row = fgetcsv($handle, "\r"))
{
    echo '$row contains: ';
    var_dump($row);

    $valueArray[] += $row[1]; // THIS IS THE LINE THAT IS NOT WORKING

    echo '$valueArray now contains ':
    var_dump($valueArray);

    $totalValue = $totalValue + $row[1];
}

echo "After loop\n";
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Done that but none of the code I have after prints or appears? When I comment that line out it works? –  Josh Pullin Aug 18 '12 at 14:12
 
@JoshPullin Explain what is $valueArray for. –  an1zhegorodov Aug 18 '12 at 14:15
 
Sorry, my line should have read $valueArray[] = $row[1];, which is PHP syntax for appending an item to an array. –  meagar Aug 18 '12 at 14:16
 
@hookman $valueArray is just a new array that I want the value from $row[1] to be added to –  Josh Pullin Aug 18 '12 at 14:20
 
@meagar I have done the debugging as suggested, and it adds to the array and prints but then just stops and doesn't reach the end of the loop. The csv file has around 260k lines in. Could this be a problem with the array and that the while loop doesn't get to finish? Like the array freezes? –  Josh Pullin Aug 18 '12 at 20:33
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up vote 0 down vote

From my understand of your script $valueArray[$amountRecords] += $row[1]; would not make any logical sense because its dependent on $amountRecords ++; which would always increase .

I think your script would work fine like this 

while ( $row = fgetcsv($handle, "\r") ) {

    $valueArray[] = $row[1]; // Put all Row[1] Into a array
    $totalValue += $row[1]; // Sum total Value 
    $amountRecords ++; //Get Record Count
}
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2  
Maintaining a record count doesn't make sense when he can simply call count($valueArray) after the loop has completed. –  meagar Aug 18 '12 at 14:17
 
+1 Good One meagar .. i agree with you .... it was just a transfer form his original script –  Baba Aug 18 '12 at 14:19
 
@Baba Yeah I have done that, but for some reason it still freezes. The csv file has over 260k lines so could this be a problem with the valueArray array not being about to cope with the amount of records getting added as the loop freezes? –  Josh Pullin Aug 18 '12 at 20:35
 
@Josh Pullin Quick Question why do you need to add it in a array ??? What your PHP memory limit ??? –  Baba Aug 20 '12 at 9:06
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