Closing nested statements

Andy128 · #1 (**permalink**) 07-25-07, 11:09 PM

I have had several people help me with coding and I understand it a fair bit. However, I cannot seem to wrap my brain around the logic behind closing multiple statements. For example:

PHP Code:


			
<?php

//Now open file

if(!file_exists("test_form_db.txt"))

{                 //A bracket

echo"<table width=550 align=center>";

echo"<tr>";

echo"<td class='th tc ol fw fc'>NO RECORDS AT THIS TIME</td>";

echo"</tr>";

echo"<tr>";

echo"<td class='th tc ol fw fc'>CHECK BACK LATER</td>";

echo"</tr>";

echo"</table>";

exit;

}                  //THIS CLOSES A

else

{                 //B bracket

echo"<table width=550 align=center>";

echo"<tr>";

echo"<th class='th tc ol fw fc'>Test Form Page</th>";

echo"</tr>";

//

$openedfile = fopen( "test_form_db.txt", 'r' );

if($openedfile)

{                         //D bracket

while (!feof( $openedfile ) )

    {                     //E bracket

        $line = trim(fgets( $openedfile ));

        if ( !empty( $line ) )

        {                //F bracket

            list( $test1,$test2,$test3, $test4, $test5) = explode( "|", $line );

/////////////////////////////////////////////////////////////////////////////////

//Display in a table

//

echo"<tr>";

echo"<td class='td tc w2 fw ol ff'>$test1</td>";

echo"</tr>";

echo"<tr>";

echo"<td class='td tc w2'>$test2</td>";

echo"</tr>";

echo"<tr>";

echo"<td class='td tc w2 fw fc'>$test3</td>";

echo"</tr>";

echo"<tr>";

echo"<td class='td tc w2'>$test4</td>";

echo"</tr>";

echo"<tr>";

echo"<td class='td tc w2'>$test5</td>";

echo"</tr>";

}

}

fclose( $openedfile );

}                     //THIS CLOSES B bracket

else

{                     //C bracket 

echo"<tr>";

echo"<td class='th w2'>Cannot open file!</td>";

echo"</tr>";

echo"</table>";

}                    //THIS CLOSES C bracket

}

?>

Which ones close D,E,F?

Any helpful lessons appreciated.

Andy

Nico · #2 (**permalink**) 07-26-07, 02:17 AM

My advice: Write your code cleaner, and you won't need comments to know which bracket closes which statement.

Personally, I indent all code inside a statement by one, like this:

PHP Code:


			
<?php

//Now open file

if (!file_exists("test_form_db.txt"))

{                 //A bracket

    echo"<table width=550 align=center>";

    echo"<tr>";

    echo"<td class='th tc ol fw fc'>NO RECORDS AT THIS TIME</td>";

    echo"</tr>";

    echo"<tr>";

    echo"<td class='th tc ol fw fc'>CHECK BACK LATER</td>";

    echo"</tr>";

    echo"</table>";

    exit;

}                  //THIS CLOSES A

else

{                 //B bracket

    echo"<table width=550 align=center>";

    echo"<tr>";

    echo"<th class='th tc ol fw fc'>Test Form Page</th>";

    echo"</tr>";

    //

    $openedfile = fopen( "test_form_db.txt", 'r' );

    

    if($openedfile)

    {                         //D bracket

        while (!feof( $openedfile ) )

        {                     //E bracket

            $line = trim(fgets( $openedfile ));

            

            if ( !empty( $line ) )

            {                //F bracket

                list( $test1,$test2,$test3, $test4, $test5) = explode( "|", $line );

                /////////////////////////////////////////////////////////////////////////////////

                //Display in a table

                //

                echo"<tr>";

                echo"<td class='td tc w2 fw ol ff'>$test1</td>";

                echo"</tr>";

                echo"<tr>";

                echo"<td class='td tc w2'>$test2</td>";

                echo"</tr>";

                echo"<tr>";

                echo"<td class='td tc w2 fw fc'>$test3</td>";

                echo"</tr>";

                echo"<tr>";

                echo"<td class='td tc w2'>$test4</td>";

                echo"</tr>";

                echo"<tr>";

                echo"<td class='td tc w2'>$test5</td>";

                echo"</tr>";

            }

        }

        

        fclose( $openedfile );

    }                     //THIS CLOSES B bracket

    else

    {                     //C bracket 

        echo"<tr>";

        echo"<td class='th w2'>Cannot open file!</td>";

        echo"</tr>";

        echo"</table>";

    }                    //THIS CLOSES C bracket

}

?>

It's much easier to read and follow.

Andy128 · #3 (**permalink**) 07-26-07, 08:31 AM

Thaks Nico-

I appreciate the tip. How ever, the logic behind the closing is what escapes me. For instance. The "D" bracket is the very last one closed before the closing tag while "E" and "F" were closed directly following the table and before the closing of the file. Is there a rule to this that I am missing or simply the logic itself.

And by cleaner, I take it that you simply meant the indentations not the logic or syntax it self of the script presented.

Andy

nova912 · #4 (**permalink**) 07-26-07, 10:32 AM

Quote:

Originally Posted by Andy128

Thaks Nico-

I appreciate the tip. How ever, the logic behind the closing is what escapes me. For instance. The "D" bracket is the very last one closed before the closing tag while "E" and "F" were closed directly following the table and before the closing of the file. Is there a rule to this that I am missing or simply the logic itself.

This is because "bracket D" is your loop, and you need to have things happen in your loop. E and F happen in your loop and will need to be closed inside of D because you started them in D, understand?

Quote:

And by cleaner, I take it that you simply meant the indentations not the logic or syntax it self of the script presented.

I'm not going to comment on the logic, but the syntax could use some work, try making your code so a majority of it is run before any HTML is output to the web browser. This can be done in your case by putting all of that echoed html into 1 string var, then echoing that string 1 time. instead of calling echo X number of times.

Andy128 · #5 (**permalink**) 07-26-07, 12:33 PM

Thanks Nova-

Quote:

try making your code so a majority of it is run before any HTML is output to the web browser. This can be done in your case by putting all of that echoed html into 1 string var, then echoing that string 1 time. instead of calling echo X number of times.

If you have the time, could you provide a small snippet of example on this?

Thanks again-

Andy

nova912 · #6 (**permalink**) 07-26-07, 12:59 PM

PHP Code:


			
<?php
$table = '';
// Start to build table
$table .= '<table>';
for($i=0;$i<10;$i++)
    {
    $table .='<tr>';
    for($j=0;$j<10;$j++)
        {
        $table .='<td>';
        $table .= 'Content for this cell of this row';
        $table .='</td>';
        }
    $table .='</tr>';
    }
$table .= '</table>';
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

    <head>
        <meta http-equiv="content-type" content="text/html;charset=utf-8" />
        <title>pre-php</title>
    </head>

    <body>
        <p><?php echo $table; ?></p>
    </body>

</html>

Andy128 · #7 (**permalink**) 07-26-07, 01:07 PM

Thanks Nova- I will sink my teeth into this straight away. Why is it that these cool examples are not covered in most books?

Any reference material you would suggest to pick up the tricks of the trade?

Andy

nova912 · #8 (**permalink**) 07-26-07, 02:02 PM

Best book I ever read on PHP, covers it all.

http://www.amazon.com/PHP-MySQL-Deve...5476502&sr=8-1