Parse error in eval

Question

Is there something wrong with using the following:

$test .= '$row[\''.$row[0].'\'].';
//When echo'ed shows
echo $test;
//$row['CustomerID'].$row['CompanyName']

//I have used it like this
eval($test)

PHP complains:

Parse error: parse error in C:\w.php(73) : eval()'d code on line 1

I can't see where the parse error is. Please help.

Update + More Detail

function get_rows(){
//This function needs to find out what columns it will query for
//so it calls get_columns()
while($row = sqlsrv_fetch_array($stmt, SQLSRV_FETCH_NUMERIC)){
 $pdf->Cell(0,10, eval($column_names) ,0,1);
}

function get_columns(){
//returns a string of the columns that need to
//be retrieved
return $column_names;
}

I have a PDF creator in function get_rows() which needs to be passed a string which is the value of the evaluated code I have shown above.

I have condensed what is happening as there is too much code.

Answer 1

You can use variables for the keys as well like this:

echo $row[$row[0]];

This will get you the value with the key that is in $row[0].

---

Edit Now that you added more information: I would just store the column names in an array and do a foreach loop to retrieve the corresponding values from $row like this:

while ($row = sqlsrv_fetch_array($stmt, SQLSRV_FETCH_NUMERIC)) {
    $value = '';
    foreach ($column_names as $column_name) {
        $value .= $row[$column_name];
    }
    $pdf->Cell(0, 10, $value, 0, 1);
}

Answer 2

Gumbo is totally right, there is absolutely no need to use eval() for this.

For the purposes of finding the actual parse error, there seems to be no semicolon behind the statement?

Answer 3

Your code always appends a . even if it is not needed. Your results should be impossible based on the code you have provided. Given your code I would expect to see this:

echo $test;
//$row['CustomerID'].$row['CompanyName'].

Note the extra dot.

Also, as Pekka pointed out, you are missing the semi-colon.

Answer 4

Quoting the manual:

eval() returns NULL unless return is called in the evaluated code"

You don't even show what $column_names contains or how it's generated so there isn't enough info to say what's wrong.

I have a PDF creator in function get_rows() which needs to be passed a string which is the value of the evaluated code I have shown above.

Why exactly do you need "eval" to generate a string?

Answer 5

I certainly agree that you don't need eval() here, but to give you an example of what I mean by "tested, self-contained example":

<?php
function insert_rows($pdf) {
  $column_names = get_evalcode();
  echo 'Debug: ', __METHOD__, ': column_names=\'', $column_names, "'\n";
  // while($row = sqlsrv_fetch_array($stmt, SQLSRV_FETCH_NUMERIC)){
    $row = array('a'=>'fA', 'b'=>'fB', 'c'=>'fC');
    $pdf->Cell(0,10, eval($column_names) ,0,1);
  //}
}

function get_evalcode(){
  $column_names = 'return $row["a"].$row["b"];';
  return $column_names;
}

class DummyPDF {
  public function Cell($p1, $p2, $string, $p4, $p5) {
    echo 'Debug: ', __METHOD__, ': ', $string, "\n";
  }
}
insert_rows(new DummyPDF);

prints

Debug: insert_rows: column_names='return $row["a"].$row["b"];'
Debug: DummyPDF::Cell: fAfB

Now you can remove the dummy implementations step-by-step and compare the differences.